BASEstar Open DAS
                    for Modicon
                    on_Digital_UNIX[TM]_________________________________
                    Release Notes

                    Operating System and Version: Digital UNIX Version
                                                  4.0

                    Software Version:             Device Access Software
                                                  for Modicon, Version
                                                  3.1-000


















                    Digital Equipment Corporation
                    Maynard, Massachusetts

 






              ________________________________________________________________
              April 1997

              Possession, use, or copying of the software described in
              this publication is authorized only pursuant to a valid
              written license from Digital or an authorized sublicensor.

              Digital Equipment 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.

              The following are trademarks of Digital Equipment
              Corporation:

              Alpha, BASEstar, DEComni, Digital, OpenVMS, TK, VAX, VMS,
              and the Digital logo.

              UNIX is a registered trademark in the United States and
              other countries licensed exclusively through X/Open Company
              Ltd.

              Modicon and Modbus are registered trademarks of AEG
              Schneider Automation.

              All other trademarks and registered trademarks are the
              property of their respective holders.

              This document was prepared using DEC DOCUMENT Version 3.0.

 














     _________________________________________________________________

                                                              Contents



           1     New and Changed Features for V3.1-000.........      1
           1.1       Support for DEComni V3.1..................      1
           1.2       Support for BASEstar Open V3.1............      1
           1.3       Support for Group Reads...................      1
           1.4       Support for TELNET........................      1
           2     Problems Fixed in This Release................      1
           2.1       Reading Data with Hex 'FF'................      1
           3     Known Restrictions............................      1
           3.1       Restriction on Devices on a Line..........      2
           4     Known Problems................................      2
           5     Documentation Errata..........................      2























                                                                   iii

 







        1 New and Changed Features for V3.1-000

              The following changes are included in this release:

        1.1 Support for DEComni V3.1

              Support was added for DEComni V3.1.

        1.2 Support for BASEstar Open V3.1

              Support was added for BASEstar Open V3.1.

        1.3 Support for Group Reads

              The DAS now supports reads of more than one variable with
              one read operation via the omni_group_variables function.
              When using BASEstar Open the SMA_MODE field in the protocol
              profile may now be set to ENABLED. Note that all variables
              defined in a group must be of the same type. For example,
              all variables must be coils or holding registers. Also,
              all values from the first address to the last address in
              the group are read by the DAS, so, in some cases, it may be
              more efficient to read variables separately rather than as
              a group.

        1.4 Support for TELNET

              TELNET support has been added to the DAS. The DAS now
              allows access to a terminal server using the TELNET
              protocol.

        2 Problems Fixed in This Release

              The following problems from the previous release were fixed
              in this release:

        2.1 Reading Data with Hex 'FF'

              A problem existed where data coming from a Modbus device
              with a value of Hex 'FF' would result in an error being
              returned to the user ("The retry count was exceeded"). This
              problem has now been fixed.

        3 Known Restrictions

              The following restrictions exist in this release:

                                                                        1

 







        3.1 Restriction on Devices on a Line

              All devices configured on a particular line must be
              accessed using a single process. This restriction exists
              because all devices on a line must share the same physical
              port.

        4 Known Problems

              There are no known problems as of this release.

        5 Documentation Errata

              There are no documentation corrections at this time.































        2