I'm trying to figure out if I can connect a generic serial device RS-232 communication device to a Quantum or Premium and be able to send the device an ASCII string of characters at 9600,8,N,1. My understanding is that the Quantum will talk Modbus RTU at this level but not Modbus ASCII.

I also do not understand if the correlation is a one-to-one. I thought Modbus was proprietary meaning that some kind of conversion would have to take place to properly receive the data on the serial device.

Basically I want to send an ASCII String on an alarm condition. Alarm goes high, out the serial port of the PLC to this device goes "Alarm 123 went high". I'm positive I can write an application that will poll it via OPC or talk directly to my HMI, but I'd like to pull this particular data via the PLC directly.

Has this been done before? Anyone have
any suggestions on where to look for a possible answer?

 

Hi
You can setup the Premium TER port for ASCII protocol if you want use RS485 or add the RS232 PCMCIA card for the PLC or RS232/485 converter. In Quantum PLC it depends on software do you use Modsoft/Concept/ProWorx/Unity.

Regards
Andrzej
www.modbus.pl

 

The DataLink DL4000-MMX will work great in your application interfacing your Quantum PLC modbus RTU to ASCII.

DL4000-MMX http://www.datalinkgateways.com/products_dl4000-mmx.htm

Mike Bunker
www.datalinkgateways.com / www.protocolconverter.com