I trying to communicate with our PowerBuilder application that is using MSComm/ole to communicate with a check weigher device via a serial port. I am able to send and receive data with some of our check weighers with no problem.

Now I need to communicate with a 9000 ICOR check weigher that uses registers. I know what registers (40002, 40007, 40460, 40476-82) to populate for the weights I'm trying to send.

The problem I'm trying to figure out is how to do this via my PowerBuilder application via modbus. I take it I'm going to send the values for the associated registers via a MSComm.Ouput command. But, how do you get these values for the registers set-up in this output command to the device. I'm going to need a modbus master driver to do this I believe.

Do you have any insight you can share with me to accomplish this task? Even if you know how to do it via Visual Basic. How would the application talk to modbus and indicate what registers to populate for the device? Do I need to have modbus master activex on my PC for the application. I downloaded modscan32 demo. Does the device have to be connected to test this application?

Thanks very much for any help! If you can explain the steps involved or how to send the values for the registers via the output command to the device.

 

Dear Carlo,

I am assuming your device is accessible through Modbus ASCII/RTU or TCP, and that it is configured as a slave (server). The registers you mentioned (40002, 40007, 40460, 40476-82) sound correct - these are in the range of holding registers. You need your PowerBuilder application to become a Modbus master (client). As I see it here are your options:

Option 1) Most difficult
PowerBuilder <--> device
This involves writing the Modbus master driver yourself to communicate directly through MSComm. As I don't program PowerBuilder myself, I can only suggest this VB code to start with: http://www.modbus.pl/downloads.htm

Option 2) Medium difficulty
PowerBuilder <--> Modbus ActiveX <--> device
For a Modbus master ActiveX, try HMITalk ActiveX: http://www.cpksoft.com.ar/home-e.htm
or Win-Tech (where you got modscan32).

Option 3) Medium difficulty
PowerBuilder <--> Modbus DLL <--> device
For a Modbus DLL, try FieldTalk / Modbus from Focus: http://www.focus-sw.com

Option 4) Easiest
PowerBuilder <--> OPC Client ActiveX <--> Modbus OPC Server <--> device
As the vendor of OPC Client software, I recommend our product OPCWare Client Developer - an ActiveX library that has been used successfully with PowerBuilder.
For the OPC Server, try Win-Tech (where you got modscan32):
http://www.win-tech.com/html/opc.htm

Regards,
Neil Kingston - email: neil<at>opcware<dot>com
Data Layers
http://www.opcware.com

 

Visit http://www.automatedsolutions.com. Automated Solutions offers a Modbus (RTU/ASCII/TCP/PLUS) ActiveX Control that can be used in any ActiveX Control container. A fully functioning evaluation version is available for download. A pre-built HMI application comes with the eval version, so you can easily familiarize yourself with your device's register layout without writing any code.