BASEstar_Open_Server_for_Compaq_Tru64_UNIX__________ Release Notes June 1999 This document contains the release notes for BASEstar Open Server Version 3.2 for Compaq Tru64 UNIX systems. Revision/Update Information: This is a revised document for the current release. Software Version: BASEstar Open Server Version 3.2 Compaq Computer Corporation Houston, Texas ________________________________________________________________ June 1999 © Digital Equipment Corporation 1999. All Rights Reserved. The software described in this guide is furnished under a license agreement or nondisclosure agreement. The software may be used or copied only in accordance with the terms of the agreement. Compaq Computer Corporation makes no representations that the use of its products in the manner described in this publication will not infringe on existing or future patent rights, nor do the descriptions contained in this publication imply the granting of licenses to make, use, or sell equipment or software in accordance with the description. COMPAQ,the Compaq logo and the Digital logo are registered in the U.S. Patent and Trademark Office. Tru64 is a trademark of Compaq Computer Corporation. The following are trademarks of Digital Equipment Corporation: Alpha AXP, BASEstar, DEC, DECmessageQ, DECnet, DECnet-DOS, DECosap, DEComni, DIGITAL, DIGITAL UNIX, FMS, LN03, MicroVAX, NAS, OpenVMS, OpenVMS Alpha, PATHWORKS, PDAS, Rdb/VMS, ReGIS, ThinWire, TK, ULTRIX, VAX, VAXcluster, VAX COBOL, VAX FORTRAN, VAX Pascal, VAX RMS, VMS/ULTRIX Connection, and VT. Microsoft and Windows NT are registered trademarks of Microsoft Corporation. The following are third-party trademarks: Other product names mentioned herein may be the trademarks of their respective companies. This document was prepared using VAX DOCUMENT, Version 2.1. _________________________________________________________________ Contents Preface................................................... v 1 Introduction and General Release Notes 1.1 Differences/Enhancements With Respect to BASEstar Open Server Version V3.1......................... 1-1 1.2 Pre-requisites................................... 1-2 1.3 BASEstar Open Inter-Version Compatibility........ 1-2 1.4 Implementation-Dependent Characteristics......... 1-2 2 Installation Release Notes 2.1 Installation Verification Procedure (UNIX platforms)....................................... 2-1 3 Modified Functionality 3.1 BASEstar Open Server Checks Client Licenses...... 3-1 3.2 AMS failover..................................... 3-2 3.3 Unlimited Number of Clients per Activity......... 3-3 4 Restrictions 4.1 Modifying Fields in a Structure_Datatype......... 4-1 4.2 No Checking of mapping_path Attribute............ 4-1 4.3 Datatype Congruency Checks....................... 4-1 4.4 Device Variable Address Checks................... 4-1 4.5 Device Time Format Not Converted................. 4-1 4.6 Spaces Not Accepted in File or Directory Names... 4-2 iii 5 Bug Fixes 5.1 Communication Errors with AMS_MON................ 5-1 5.2 DDM and Variable Length Device Variables......... 5-1 5.3 DDM Crash Caused by Incomplete Local VMD......... 5-1 5.4 DTM Memory Leak with Mapped_Data_Points.......... 5-1 5.5 Linked Variables and AMS......................... 5-2 5.6 User Port Recovery............................... 5-2 5.7 Error with snapshot files........................ 5-2 5.8 DDM Crash........................................ 5-2 5.9 MGM Server Memory Leak........................... 5-2 5.10 Get_value and Expression Update.................. 5-2 5.11 LINK_DOWN Status and Expressions................. 5-2 5.12 AMS can't terminate ENCAPSULATED programs........ 5-3 5.13 bstr_reference_set()............................. 5-3 5.14 Trace database and COM_SERVER.................... 5-3 5.15 CREATE TRIGGER fails with INVALID_OPERAND........ 5-3 5.16 Y2k problem in log file.......................... 5-3 5.17 aligment warnings................................ 5-4 5.18 Stack overflow in cli_bstr....................... 5-4 5.19 Packet server loop............................... 5-4 5.20 DTM memory leak.................................. 5-5 5.21 Execute actor hang............................... 5-5 6 Known Problems 6.1 Support of Wildcard Characters................... 6-1 6.2 Output from the CLI.............................. 6-1 6.3 Interrupting Execution of a Command File......... 6-1 6.4 Resizing a Terminal Window....................... 6-2 6.5 Referencing an Object After Server Shutdown...... 6-2 6.6 BASEstar Open TIME data type..................... 6-2 6.7 Using bstr_initialize After bstr_finish.......... 6-3 6.8 Hostname Length Restriction...................... 6-3 6.9 Assigning a Default Value to a Data_Point........ 6-3 7 Documentation Release Notes 7.1 BASEstar Open Application Programming Interface.. 7-1 7.1.1 General ....................................... 7-1 7.1.2 Incorrect Description of bstr_reference_recover Procedure...................................... 7-1 7.2 BASEstar Open Messages........................... 7-1 7.2.1 General Purpose and Common Services Messages .. 7-2 iv Tables 1-1 Data Management Characteristics ............... 1-3 1-2 Event Management Characteristics .............. 1-4 1-3 Packet Management Characteristics ............. 1-5 1-4 Application Management - Configurable objects........................................ 1-5 1-5 Program/Environment Parameter File ............ 1-6 v _________________________________________________________________ Preface Kit Identification You can identify this kit by the identifier that BASEstar Open Server processes print on the log files: o Compaq Tru64 UNIX: "BASEstar Open V3.2 (BSTBASE320)" v 1 _________________________________________________________________ Introduction and General Release Notes The structure of this document is as follows: o Chapter 1 provides a basic introduction to BASEstar Open Server Version 3.2. o Chapter 2 contains release notes relevant to the installation of BASEstar Open Server Version 3.2 on Compaq Tru64 UNIX platforms. o Chapter 3 describes the new and modified functionality with respect to BASEstar Open Server Version V3.1 o Chapter 4 describes restrictions that apply to BASEstar Open Server Version 3.2. o Chapter 5 describes BASEstar Open Server bugs since Version V3.1 that have been fixed in Version 3.2. o Chapter 6 describes the problems known to exist in BASEstar Open Server Version 3.2. o Chapter 7 contains release notes concerning documentation issues that have arisen since BASEstar Open Server Version V3.1. 1.1 Differences/Enhancements With Respect to BASEstar Open Server Version V3.1 BASEstar Open Server Version 3.2 is a maintenance release for BASEstar Open Server Version V3.1. and in addition it provides some new features. Introduction and General Release Notes 1-1 Introduction and General Release Notes 1.2 Pre-requisites 1.2 Pre-requisites BASEstar Open Server for Compaq Tru64 UNIX runs on the following architecture and software configurations: - Alpha processor The BASEstar Open Server SPD contains a comprehensive list of the processors supported, together with any restrictions. - Digital UNIX Version 3.2C or higher. - Compaq Tru64 UNIX Version 4.0F or higher. 1.3 BASEstar Open Inter-Version Compatibility o BASEstar Open Version 3.2 creates snapshots that are compatible with BASEstar Open Version 3.1. 1.4 Implementation-Dependent Characteristics The tables that follow contain details of the characteristics implemented in BASEstar Open services. 1-2 Introduction and General Release Notes Introduction and General Release Notes 1.4 Implementation-Dependent Characteristics Table_1-1_Data_Management_Characteristics__________________ Description_______________________________Value____________ Maximum number of Activities (with AMS) 32 Maximum number of Activities (without 1 AMS) Maximum number of objects in a Domain No limit Maximum number of Data_Points in a Data_ No limit Point_Set Maximum Data_Point size 64512 bytes Maximum number of Triggers associated No limit with a Data_Point Maximum number of Trigger Event 1024 parameters Maximum number of Trigger Filter 33 parameters Maximum number of operands in a Filter 33 expression Maximum number of operators in a Filter 32 expression Maximum_number_of_clients_per_Activity____No_limit_________ Introduction and General Release Notes 1-3 Introduction and General Release Notes 1.4 Implementation-Dependent Characteristics Table_1-2_Event_Management_Characteristics_________________ Description_______________________________Value____________ Maximum number of Activities (with AMS) 32 Maximum number of Activities (without 1 AMS) Maximum number of objects in a Domain No limit Maximum number of Events in an Event_Set No limit Maximum number of Event parameters 1024 Maximum Event parameter size 64512 bytes Maximum number of clients per Activity No limit Maximum number of Enboxes bounded to a No limit client Maximum notification size (user Enbox) 8192 bytes Maximum notification size (system Enbox) No limit Maximum number of asynchronous requests 10 pending on a system Enbox Maximum number of synchronous requests 1 pending_on_a_system_Enbox__________________________________ 1-4 Introduction and General Release Notes Introduction and General Release Notes 1.4 Implementation-Dependent Characteristics Table_1-3_Packet_Management_Characteristics________________ Description_______________________________Value____________ Maximum number of Activities (with AMS) 32 Maximum number of Activities (without 1 AMS) Maximum number of objects in a Domain No limit Maximum number of input Packet 64 parameters Maximum number of output Packet 64 parameters Maximum Packet parameter size 64512 bytes Maximum number of clients per activity No limit Maximum number of ports bounded to a No limit client Maximum notification size (system Port) No limit Maximum number of asynchronous requests 10 pending on a system Port Maximum number of synchronous requests 1 pending_on_a_system_Port___________________________________ Table_1-4_Application_Management_-_Configurable_objects____ Resource________________________Maximum_value______________ Maximum number of Activities 32[1] per program Maximum number of Nodes 64 Maximum number of Actors 400 Maximum number of Programs 400 Maximum number of Activities 400 [1]Only_for_DATA,_EVENT,_PACKET_and_DEVICE_Programs._No____ limit for USER Programs ___________________________________________________________ Table 1-5 lists the maximum values associated with the Program/Environment parameter file. Introduction and General Release Notes 1-5 Introduction and General Release Notes 1.4 Implementation-Dependent Characteristics Table_1-5_Program/Environment_Parameter_File_______________ Resource________________________Maximum_value______________ Maximum input line length 256 Maximum number of lines No limit Maximum length of file names 254 Maximum number of env pair per 128 Program Maximum number of arg pair per 128 Program____________________________________________________ 1-6 Introduction and General Release Notes 2 _________________________________________________________________ Installation Release Notes 2.1 Installation Verification Procedure (UNIX platforms) To run the BASEstar Open Installation Verification Procedure (IVP) and the setup procedures, you must configure TCP/IP on the node where you intend to install the product. To check that your node is configured properly, type the following command: $ telnet `hostname` If you do not receive the login prompt, ask your system manager to check that TCP/IP has been configured correctly on your system. Installation Release Notes 2-1 3 _________________________________________________________________ Modified Functionality This chapter describes all BASEstar Open functionality that has been modified with respect to Version 3.1. 3.1 BASEstar Open Server Checks Client Licenses With Version 3.2, a Version 3.2 BASEstar Open Client no longer requires a local Client licence; however, the BASEstar Open Server Version 3.2 environment to which a Client connects, checks for an available Client-Connection slot. A BASEstar Open Version 3.2 Server environment provides initially as many Client-Connection slots as they are granted by the new Client-Connection licences. These licences can be bought with a value of 1,5, or 10 units. Multiple licences can be cumulated. When a BASEstar Open Version 3.2 Client node connects to a BASEstar Open Version 3.2 Server environment, it consumes one slot and returns it when it disconnects; a Client can connect to a Server only if there is at least one slot available. One Client-Connection slot is required for each client node; this is independent on the client node platform and on how many BASEstar Open client applications are running on the node. The number of available Client-Connection licenses is initially set by the BASEstar Open Master LNS Server when the BASEstar Open node processes are started (the initial Master LNS Server is usually the Primary LNS Server; it may be the Secondary LNS Server if this is configured and starts before the primary server). Modified Functionality 3-1 Modified Functionality 3.1 BASEstar Open Server Checks Client Licenses The first Master LNS Server gets the Client-Connection licenses information from the node where it starts, therefore the corresponding LMF licenses or swkeys must be loaded on all the nodes where the first Master LNS Server may be activated. The number of available Client-Connection slots is reported in the node log file (the file BASESTARNODE.LOG or BASESTAR.log for Windows NT systems), and it is associated to the identifier BSTR_S_COM_LNS_GRANTED_LIC. If additional Client-Connection licenses are added, they can be taken into consideration by BASEstar Open if the BASEstar Open nodes are shut down and started again, or if the LNS Server is forced to reload the total number of Client-Connection licenses. The forced evaluation can be obtained by running the following command from the Operating System command line: > com_control lns_reload_pak -d lnssr_BSTR On Compaq Tru64 UNIX and OpenVMS systems, the Client- Connection licences are provided by LMF licences or software keys mechanism. When the proper LMF licences are missing, software keys (strings of 20 character) for looked for to establish the initial number of Client-Connection slots. If present, they are expected to be stored in the file sw_ key_file.dat in the BASEstar etc directory. 3.2 AMS failover AMS server failover usually works for five times when going from node 1 to node 2, then 2 to 1, etc. Now it is possible to override the default value by setting the BSTR_AMS_ RESTART_MAX variable in the AMS environment to any required value. BSTR_AMS_RESTART_MAX equal to 0 means infinite. 3-2 Modified Functionality Modified Functionality 3.3 Unlimited Number of Clients per Activity 3.3 Unlimited Number of Clients per Activity The maximum number of clients per Activity was limited to 40. Although 40 remains the default value in BASEstar Open Version 3.2 (see Table 1-1, Table 1-2 and Table 1-3), you can assign a new maximum limit to the BSTR_MAX_CLIENTS_PER_ ACTIVITY environment variable. Modified Functionality 3-3 4 _________________________________________________________________ Restrictions This chapter describes all restrictions that apply to BASEstar Open Server Version 3.2. 4.1 Modifying Fields in a Structure_Datatype After creating a Structure_Datatype, it is not possible to modify or delete a field in the datatype. You must delete the datatype and then recreate it with the required fields. 4.2 No Checking of mapping_path Attribute When creating or modifying a Filter or a Mapped_Data_ Point, BASEstar Open does not perform validity checks on the mapping_path attribute. 4.3 Datatype Congruency Checks When creating or modifying a Trigger, BASEstar Open does not check the datatype congruency of Filter and Event parameters with the Filter expression and the Event datatype. 4.4 Device Variable Address Checks When creating or modifying a Named_ or Unnamed_Variable, BASEstar Open does not check the address. 4.5 Device Time Format Not Converted If the type of a Device_Data_Point or the type of field in a Device_Data_Point is TIME, BASEstar Open does not convert the corresponding value to the BASEstar Open internal format. Therefore, the BASEstar Open time routines do not work. Restrictions 4-1 Restrictions 4.6 Spaces Not Accepted in File or Directory Names 4.6 Spaces Not Accepted in File or Directory Names BASEstar Open cannot handle file or directory names that contain space characters. This limitation extends to the names of snapshot and work directories (if the user decides to modify the default name). 4-2 Restrictions 5 _________________________________________________________________ Bug Fixes This chapter describes BASEstar Open Server bugs that have been fixed since Version 3.1. 5.1 Communication Errors with AMS_MON The Application Management Services server did not handle properly in some cases an error detected by the communication library. This problem caused AMS_MON to log the error E_BSTR_S_COM_LOGNOQED. This problem no longer exists in BASEstar Open Version Version 3.2. 5.2 DDM and Variable Length Device Variables The Data & Device Manager did not manage correctly the values of VARIABLE_LEN device variables, because of different size formats handled by BASEstar Open and DEComni API. This problem no longer exists in BASEstar Open Version 3.2. 5.3 DDM Crash Caused by Incomplete Local VMD The Data & Device manager did not manage correctly the dnt_ client array for the local VMD: this problem might cause a DDM crash. This problem no longer exists in BASEstar Open Version 3.2. 5.4 DTM Memory Leak with Mapped_Data_Points The Data Services server did not free correctly the allocated memory when handling Mapped_Data_Points. This problem no longer exists in BASEstar Open Version 3.2. Bug Fixes 5-1 Bug Fixes 5.5 Linked Variables and AMS 5.5 Linked Variables and AMS BASEstar Open in some cases did not manage properly linked variables if the Application Management Services server was not running. This problem no longer exists in BASEstar Open Version 3.2. 5.6 User Port Recovery BASEstar Open Server did not correctly perform the recovery procedure on user Port objects. This problem no longer exists in BASEstar Open Version 3.2. 5.7 Error with snapshot files BASEstar Open did not manage properly snapshots with names containing non-numeric characters. This problem no longer exists in BASEstar Open Version 3.2. 5.8 DDM Crash A BASEstar Open Data & Device server might occasionally crash because of a truncation of a pointer to 32 bits . This problem no longer exists in BASEstar Open Version 3.2. 5.9 MGM Server Memory Leak The BASEstar Open MGM Server generated a memory leak when two application programs exchanged data via the Port/Packet mechanism. This problem no longer exists in BASEstar Open Version 3.2. 5.10 Get_value and Expression Update A get_value operation that modifiedthe status/value of an operand did not update the associated expression. This problem no longer exists in BASEstar Open Version 3.2. 5.11 LINK_DOWN Status and Expressions A LINK_DOWN status change did not update the associated expression. This problem no longer exists in BASEstar Open Version 3.2. 5-2 Bug Fixes Bug Fixes 5.12 AMS can't terminate ENCAPSULATED programs 5.12 AMS can't terminate ENCAPSULATED programs ENCAPSULATED programs started up by AMS can not terminate, they remain alive after "terminate actor" execution. The only way to stop the process is to kill it via "kill -9". The problem, due to a wrong management of sigprocmask, has been fixed in Version 3.2. 5.13 bstr_reference_set() Calling bstr_reference_set() with 'type' (3rd argument) set to: BSTR_C_ON_FIRST_USE | BSTR_C_RECOVERY_REQ resulted in an unusable reference. bstr_reference_set() returned BSTR_S_NORMAL, but as soon as one attempted to use the reference, for example in a bstr_data_point_get_value() call, BSTR_S_INTERNAL_ERROR was returned. The problem has been fixed in Version 3.2. 5.14 Trace database and COM_SERVER The default trace realm database created by bstr_realm_ setup_node does not manage well COM_SERVER. On UNIX the tracepoint created was PC_SERVER while the string used by COM_SERVER was COM_SERVER. On VMS the process selector related to COM_SERVER was not inserted. The problem has been fixed in Version 3.2. 5.15 CREATE TRIGGER fails with INVALID_OPERAND The creation of a trigger failed when the associated filter has an EXPRESSION containing any of the #S , #OS, #V and #OV operands, and the associated data_point is either an ARRAY or a STRUCTURE. That was a regression now fixed. 5.16 Y2k problem in log file The timestamp in log file was ambiguous in case of year 2000 as the year was printed as 100 (offset from 1900 base year). With this version, years are now displayed with four digits. Bug Fixes 5-3 Bug Fixes 5.17 aligment warnings 5.17 aligment warnings The following cli_bstr commands result in aligment warnings on Compaq Tru64 UNIX: create array_datatype STRING_3 \ -datatype VISIBLE_CHAR \ -array_type FIXED_LEN \ -num_of_elements 3 \ -description "3 Character String" create structure_datatype BUG_STRUCT -members (s:STRING_3 bug_d:D_FLOAT) create array_datatype BUG_ARRAY -datatype BUG_STRUCT \ -array_type VARIABLE_LEN -num_of_elements 5 crea data_point bug_demo -datatype BUG_ARRAY BSTR> get value data_point bug_demo varying array[5] of BUG_STRUCT (now 3) [ 0]: structure BUG_STRUCT { s: array[3] of VISIBLE_CHAR 123 bug_d: Unaligned access pid=7528 va=47c94 pc=120077e6c ra=120076b8c type=ldt 1.200000 The problem has been fixed BASEstar Open Version 3.2. 5.18 Stack overflow in cli_bstr It happened that running cli_bstr the following message appear: Stack overflow: pid 28148, proc cli_bstr .... Memory fault (coredump) It was due to a bug in the datatypes VODB navigation. The problem has been fixed BASEstar Open Version 3.2. 5.19 Packet server loop The packet server sometimes behaved in strange ways, a request made to it (for example with cli_bstr) just hangs forever, Meanwhile, the realm logfile is filled by messages like the following: 5-4 Bug Fixes Bug Fixes 5.19 Packet server loop MGM_SERVER : E-BSTR_S_COM_NOREQUEST: No request to be answered The problem has been fixed in BASEstar Open Version 3.2. 5.20 DTM memory leak A memory leak problem was caused by the following sceanario: o one DEVICE program managing one or more VMDs and getting values from them either via POLLING_SETS or by means of "Info Report" messages sent by the devices. o one DATA program managing device_data_points with UPDATE_POLICY = [INIT_]UNSOLICITED. The DATA program's virtual memory size kept growing as long as the DEVICE program pushes messages to it. The problem has been fixed in BASEstar Open Version 3.2. 5.21 Execute actor hang It could happen that the execute actor hungs when the node on which the actor should be excecuted had a "wrong" physical name. The problem has been fixed in BASEstar Open Version 3.2. Bug Fixes 5-5 6 _________________________________________________________________ Known Problems This chapter describes the problems known to exist in BASEstar Open Server Version 3.2. 6.1 Support of Wildcard Characters The following commands do not support wildcard characters: o GET VALUE DATA_POINT o GET VALUE NAMED_VARIABLE o GET VALUE UNNAMED_VARIABLE o GET INFO ENBOX o GET INFO ACTIVITY o GET INFO ACTOR o GET INFO PORT o GET STATUS DATA_POINT o GET STATISTICS all objects 6.2 Output from the CLI Output from the CLI is not paged. 6.3 Interrupting Execution of a Command File If you interrupt the execution of a BASEstar Open CLI command file activated from the CLI (SOURCE or RUN commands), BASEstar Open forces an exit from the CLI. Known Problems 6-1 Known Problems 6.4 Resizing a Terminal Window 6.4 Resizing a Terminal Window The resizing of a DECwindows Motif terminal window may have an unpredictable effect on command editing and history mechanisms. 6.5 Referencing an Object After Server Shutdown If an application includes a reference to a BASEstar Open object, and the server managing the object goes down, the reference becomes invalid. Therefore, if Application Management Services restart the server (either on the same Node or on a different Node), the application should: o Unset the original reference o Create a new reference 6.6 BASEstar Open TIME data type TIME data type can have different values in BASEstar Open distributed environment when at least one node is a VMS node. If the time is in the daylight saving range there is a difference of (+/-) 1 hour among VMS and the other systems. In the following example a put value data_point of datatype TIME is considered. On UNIX (WNT) node: BSTR> crea data_point /dp_time -datatype TIME BSTR> put value data_point /dp_time (Date - [Wday] MON DD hh:mm:ss[.usec] YYYY): Aug 10 10:20:00 1999 On VMS node: BSTR> get value data_point /dp_time Tue Aug 10 09:20:00.000000 1999 BSTR> put value data_point /dp_time (Date - [Wday] MON DD hh:mm:ss[.usec] YYYY): Aug 10 10:20:00 1999 On UNIX (WNT) node BSTR> get value data_point /dp_time Tue Aug 10 11:20:00.000000 1999 6-2 Known Problems Known Problems 6.7 Using bstr_initialize After bstr_finish 6.7 Using bstr_initialize After bstr_finish If you use the bstr_finish command in a multithreaded environment, BASEstar Open fails to release all the resources allocated for calls that were interrupted. Therefore, an application cannot invoke bstr_initialize after bstr_finish. 6.8 Hostname Length Restriction BASEstar Open Version 3.2 does not support hostnames that are greater than 32 characters in length. 6.9 Assigning a Default Value to a Data_Point BASEstar Open does not allow you to assign a default value to a simple datatype of the F_FLOAT or D_FLOAT type. Known Problems 6-3 7 _________________________________________________________________ Documentation Release Notes This section details any errors in the BASEstar Open documentation set. 7.1 BASEstar Open Application Programming Interface This section lists any documentation errors in the BASEstar Open Application Programming Interface manual. 7.1.1 General Some of the BASEstar Open API functions do not fully implement all the capabilities made available by the "request control block". However, these limitations are not always highlighted in the BASEstar Open Application Programming Interface manual. For example, if you use the bstr_data_point_get_value routine with a timeout value set in the request control block, BASEstar Open returns the status code "Not implemented". 7.1.2 Incorrect Description of bstr_reference_recover Procedure Previous versions of the BASEstar Open Application Programming Interface manual fail to point out that it is not possible to use the bstr_reference_recover procedure to recover applications on server nodes following a system failure. 7.2 BASEstar Open Messages This section lists any documentation errors in the BASEstar Open Messages manual. Documentation Release Notes 7-1 Documentation Release Notes 7.2 BASEstar Open Messages 7.2.1 General Purpose and Common Services Messages The list of messages in the General Purpose and Common Services sections contains an incorrect explanation for BSTR_S_READ_ONLY. The full text associated with the message should be as follows: BSTR_S_READ_ONLY The Data_Point cannot be written Severity: Error Explanation: The current value of the specified Data_Point can only be read (for example, in the case of a Mapped_Data_ Point that is mapped to a Data_Point which is in turn linked as producer to one or more unsolicited consumers). User Action: Examine the source program and correct the problem. 7-2 Documentation Release Notes