| Previous | Contents | Index |
The DAS for AB INTERCHANGE software requires a message port quota of 100,000. The BASEstar Classic parameter BCC$MAX_PORT_QUOTA must be set greater than or equal to this value.
Use the BASEstar Classic CLI SHOW PARAMETER command to review the value
of the maximum port quota parameter. If necessary, use the SET
PARAMETER command to adjust it. For more information refer to the
BASEstar Classic Configuration and Tuning Guide.
2.3.4 Setting the SPT Block Parameter
The ILAN$MAX_SPT_REQUESTS parameter specifies the total number of blocks that can be allocated in the SPT (support) global section. DASes use blocks in the global section for storing data structures and for doing device I/O. The SPT global section is sized by calculating the number of SMALL, MEDIUM, LARGE and EXTRA LARGE blocks that the section should contain. Some blocks remain for the life of a device and some are allocated and deallocated for each I/O operation. Table 2-6 shows the static blocks of each size that are used by the DAS.
| Block Size | Quantity1 | Block Type |
|---|---|---|
| MEDIUM | 2 | Device |
| 1 | Line | |
| 1 | DTL Server | |
| 1 | DAS | |
| SMALL | 1 | Device 2 |
| 1 | Unsolicited point 2 |
Table 2-7 shows the dynamic blocks of each size that are used by the DAS. These blocks are created and deleted as the device does I/O.
| Block Size | Quantity1 | I/O Type |
|---|---|---|
| LARGE | 1 | Status |
| MEDIUM | 1 | Read 2, write 2, upload, download |
| SMALL | 3 | Any 3 |
The size of the SPT global section can be tuned by changing the
percentage of each kind of block that is created. Refer to the
BASEstar Classic Configuration and Tuning Guide for instructions on changing the percentage of each size
of block that is created in the global section.
2.3.5 Setting DAS-Specific Parameters
The following sections describe how to set the following DAS-specific BASEstar Classic parameters:
None of the parameters created for the DAS for AB INTERCHANGE software are dynamic.
BASEstar Classic device connection management must be shut down and
started again before parameter modifications become effective.
2.3.5.1 ILAN$DTLSRV_PRIORITY
The ILAN$DTLSRV_PRIORITY parameter sets the priority of the INTERCHANGE server process, DCM_DTL$SRV. Values are as follows:
| Default value | 6 |
| Minimum value | 1 |
| Maximum value | 10 |
Use this parameter in conjunction with the ILAN$DTL_CYCLE_TIME
parameter to balance the performance of the INTERCHANGE server
process. A high priority setting will give more CPU time to the server
process for collecting data and processing requests. Understand,
however, that increasing this setting may be at the expense of the
applications using this data. Refer to the appropriate documentation on
OpenVMS system management and tuning for more information.
2.3.5.2 ILAN$DTL_BACKLOG
The ILAN$DTL_BACKLOG parameter sets the number of unsolicited messages which will be buffered by the INTERCHANGE software. Values are as follows:
| Default value | 5 messages |
| Minimum value | 1 message |
| Maximum value | 40 messages |
The ILAN$DTL_CYCLE_TIME parameter controls the maximum amount of time the INTERCHANGE server process waits for DTL I/O completion before checking for requests from the NI. Values are as follows:
| Default value | 70 milliseconds |
| Minimum value | 5 milliseconds |
| Maximum value | 1,000 milliseconds |
Generally, the smaller the cycle time, the faster the server will
respond to the NI requests. If the cycle time is too small, however,
the server will consume CPU time checking for requests.
2.3.5.4 ILAN$DTL_DWNL_FLAGS
The ILAN$DTL_DWNL_FLAGS parameter sets the default behavior of the download function. This default behavior may be overridden by using /QUALIFIER option on the download command. The flags specified in a download command are logically ORed with those specified by ILAN$DTL_DWNL_FLAGS.
The default value for ILAN$DTL_DWNL_FLAGS is MATCH. This flag requires
that the device type, series, and revision match that of the file being
downloaded. For more information on valid download flags that can be
used for this parameter, refer to Table 3-8.
2.3.5.5 ILAN$DTL_MAX_ELEMENTS
The ILAN$DTL_MAX_ELEMENTS parameter controls the maximum number of elements the INTERCHANGE server process can define; that is, the expected number of outstanding solicited requests and the number of unsolicited requests combined. Values are as follows:
| Default value | 500 elements |
| Minimum value | 50 elements |
| Maximum value | 100,000 elements |
The value of ILAN$DTL_MAX_ELEMENTS must be greater than the value of
ILAN$DTL_MAX_UNSOL_ELEMENTS. Note that ILAN$DTL_MAX_ELEMENTS only
affects the number of points that can be defined as unsolicited and
simultaneous pending data reads/writes. The parameter does not affect
the number of physical points that can be defined on a BASEstar Classic
system.
2.3.5.6 ILAN$DTL_MAX_UNSOL_ELEMENTS
The ILAN$DTL_MAX_UNSOL_ELEMENTS parameter controls the maximum number of elements that can be defined as unsolicited phypoints. This number is deducted from the value of ILAN$DTL_MAX_ELEMENTS. Values are as follows:
| Default value | 50 phypoints |
| Minimum value | 50 phypoints |
| Maximum value | 10,000 phypoints |
The value of ILAN$DTL_MAX_UNSOL_ELEMENTS must be less than
ILAN$DTL_MAX_ELEMENTS.
2.3.5.7 ILAN$DTL_SCMP_FLAGS
The ILAN$DTL_SCMP_FLAGS parameter sets the default behavior of the simple file compare function.
The default value for ILAN$DTL_SCMP_FLAGS is
ALL,NODATATABLES,NOREVISION. This value will have the compare operation
check everything except the data tables and the PLC revision. For more
information on valid simple file compare flags which may be used for
this parameter, refer to Table 3-12.
2.3.5.8 ILAN$DTL_TIMEOUT
The ILAN$DTL_TIMEOUT parameter determines the timeout value for all DTL I/O calls. Values are as follows:
| Default value | 1,000 milliseconds |
| Minimum value | 1,000 milliseconds |
| Maximum value | 600,000 milliseconds |
The value of ILAN$DTL_TIMEOUT should be less than the shortest /TIMEOUT
of the INTERCHANGE DAS device definitions. The desired behavior is to
have the internal INTERCHANGE DTL call timeout before the BASEstar
Classic device connect management request. If the BASEstar Classic
request times out first, a cancellation request is attempted and any
requests completion is ignored. Because INTERCHANGE does not support
cancellation of requests, the actual INTERCHANGE DTL request may have
successfully completed, yet give the incorrect impression that the
INTERCHANGE function was not completed.
2.3.5.9 ILAN$DTL_UDC_TIMEOUT
The ILAN$DTL_UDC_TIMEOUT parameter determines the timeout value for all INTERCHANGE upload, download and compare calls. Values are as follows:
| Default value | 300000 milliseconds |
| Minimum value | 1000 milliseconds |
| Maximum value | 3600000 milliseconds |
The value of ILAN$DTL_UDC_TIMEOUT should be less than the shortest
/TIMEOUT of the INTERCHANGE DAS device definitions. The desired
behavior is to have the internal INTERCHANGE DTL call timeout before
the BASEstar Classic device connect management request. If the BASEstar
Classic request times out first, a cancellation request is attempted
and any requests completion is ignored. Because INTERCHANGE does not
support cancellation of requests, the actual INTERCHANGE DTL request
may have successfully completed, yet give the incorrect impression that
the INTERCHANGE function was not completed.
2.3.5.10 ILAN$DTL_UPL_FLAGS
The ILAN$DTL_UPL_FLAGS parameter sets the default behavior of the upload function. This default behavior may be overridden by using /QUALIFIER option on the upload command. The flags specified in a upload command are logically ORed with those specified by ILAN$DTL_UPL_FLAGS.
The default value for ILAN$DTL_UPL_FLAGS is NORUNNING,NOFAULT, which
requires that the device not be in RUN mode and that it not be faulted.
For more information on valid upload flags which may be used for this
parameter, refer to Table 3-9.
2.3.5.11 ILAN$DTL_DUP_EI_ID
The ILAN$DTL_DUP_EI_ID parameter allows the DAS to communicate to more than forty (40) Ethernet Interfaces. The maximum number of Ethernet Interface IDs is forty (40). This maximum is a limit imposed by INTERCHANGE software. The DAS will by default allocate a new Ethernet Interface ID whenever it communicates to a new Ethernet Interface. However, if this parameter is set to "1", then the DAS wil allocate up to forty (40) Ethernet Interfaces IDs per DTL server process, rather than using a total of forty (40) IDs for all DTL server processes.
If this parameter is set, then the DAS will create up to sixty-four
(64) DTL server processes, with each process using Ethernet Interface
IDs from 1-40. The number of DTL server processes can be tuned by
explicitly specifying the server process to use when communicating to a
particular Ethernet Interface. See Section 2.3.2.2 for details on
configuring a path to explicitly specify the DTL server to use when
communicating.
2.3.6 Setting the DTL Server Process Quotas
The DAS for AB INTERCHANGE software allows you to tune the values of process quotas for the DCM_DTL$SRV_X process. Process parameters are read from the file BCC$SYSDATA:DCM_DTL$SRV_QUOTAS.DAT when a new DCM_DTL$SRV process is created.
Process quotas may need to be tuned depending on the number of devices and points configured and the throughput rate of requests through the server. To adjust a quota for the server process do the following:
The new quotas will be in effect the next time the server process is
started up by the DAS for AB INTERCHANGE software. The DCM_DTL$SRV_STOP utility can be
used to shutdown running server processes without shutting down
BASEstar Classic DCM.
2.3.7 Setting Up Plant-Floor Equipment
To set up your plant-floor equipment, refer to the Allen-Bradley documentation for your specific device.
While setting up the plant-floor equipment, you should record the following information that will be required for setting up the BASEstar Classic path and device definitions:
| Previous | Next | Contents | Index |