CompactLogix read from Floboss 107

[himy19]

I need to be able to retrieve data from an Emerson Floboss 107. I've never done this, and it is probably the only time I'll have to. I could spend days reading through literature to learn how to do this, ot I could ask if anyone here can clue me in. I prefer to ask the experts. Please, if you know how to do this I would appreciate any and all help. Thanks.

 

[Ken Roach]

Have you already selected a communication module ? How far away is the Floboss 107 from the CompactLogix ?

Since the Floboss supports Modbus RTU and Modbus/TCP, a Prosoft module or gateway device is my first recommendation. While the MVI69-MCM module is moderately expensive, it is very reliable and easy to use.

 

[himy19]

This a pro-bono effort, so we're trying not to spend extra money. I was hoping there was a way to set up an ASCII string that would spit out of Comm 2 over serial.

 

[Ken Roach]

There's always a tradeoff between time/effort/difficulty and money, isn't there ?

You can implement Modbus RTU on the serial port of a CompactLogix controller using an example program included with RSLogix 5000; look in the Sample projects folder. You could also implement Modbus ASCII but I wouldn't because you couldn't re-use any of the sample logic.

This takes up quite a bit of memory if you implement the whole thing. I have previously cut it down to just a few pre-defined Modbus query strings and the Modbus parser and CRC check routine.

The first steps are to determine if you're going to use Modbus RTU over RS-232 or RS-485 or if you're going to try to use Ethernet. From my reading of the documentation, the easiest thing to do is use the Local Operator Interface (LOI) RS-232 port on the Floboss.

A quick search of the PLCTalk Forums finds some users with Floboss and Modbus experience (elmatador and redviper), both in Alberta. Maybe they'll see your post next week.

Do you know which values or registers you need to read from the Floboss computer ?

 

[CaseyRAS]

I'm not sure if you got tye answer you were looking for, but I'd be happy to help out. You can speak Modbus over any of the communication ports, and if RS232 is prefered, there is a second port on the CPU card just for that. The LOI port is traditionally reserved as the Local Operator Interface. If you want to know more, just let me know.