Applies To:
  • CitectSCADA 1.00 1.01 1.10 1.11 1.20 2.00 2.01 3.x

The SA85 Modicon MBPlus Host adaptor now ships with a Device Driver called MBPHOST.SYS. If you use this with Citect you may experience problems along the lines of Standby Units not taking over and PLCs going offline for no valid reason.

We have found that this is due to the error codes from the Modicon Device Driver (MBPHOST.SYS) being changed or coded incorrectly.


If you are running Citect Version 3.10 or earlier:
Use the SA85.SYS Device Driver that is supplied with Citect. You will find this in the CITECT\BIN directory. Follow the normal instructions for installing this driver. The line in your CONFIG.SYS file will be similar to the following.

Device=c:\citect\bin\sa85.sys /mc800 /n0 /s5b /r2

If you are running Citect V3.21 or later:
Use the MBHOST.SYS file in place of SA85.SYS, the command line options for both are identical eg:

Device=c:\citect\bin\MBPHOST.SYS /mc800 /n0 /s5b /r2

MBPHOST.SYS can be obtained from your Modicon disks (with your SA85 card) or directly from AEG Schneider Automation.

If you are testing an installation:
Also supplied on the disk is the Modbus plus network utility, MBPSTAT.EXE. You can use it to monitor activity on the modbus network. When debugging communications run this utility FIRST, before starting Citect to test the SA85 card and the modbus network.

Running under DOS, change to the directory containing MBPSTAT.EXE and type "MBPSTAT /S5B" (Netbios interrupt 5B). When the program starts it will prompt for the board number (0 if you have just one SA85 installed).

The first program option '1 Set Routing Parameters', lets you specify a routing path. It also displays the Modbus adapter card number and its node address - if it is set up correctly.

The second option '2 Monitor Network Activity', lists the nodes that exist on the specifyed routing path and reads global data from each node and displays the number of words read. Once you get this working then start up Citect.