GE Series 90 Serial Data

msdooley

Member
Join Date
Jun 2003
Location
Alaska
Posts
13
What cards and program does one use in a GE Fanuc Series 90 to receive serial data and then parse that data to the %R registers? The incoming data is RS232 (modem) The data is intermitent, varying buffer lengths, and is not delimited in any fashion. It does have an LRC byte with each packet of data.
Thank you ! :p
 
It sounds like a job for a Programmable Coprocessor Module. The PCM has a BASIC language interpreter and two serial ports. It can receive data through the serial port, send out any acknowledgement that the sending unit may require, and write the data to %R memory in the CPU module. Probably most of the PCM modles in use are doing something like that.
 
I received the following PM:

Thanks for the quick answer Steve. I brought home a few Fanuc manuals last weekend, but quite frankly, all of the part numbers began to blur. Do you know as a site to see examples of their basic language?
M Dooley

And my response:

For a 90-70, the part number is IC697PCM711. It supports a memory expansion card, but for a small program you probably won't need one. The manual for the module is GFK-0255*, for the MegaBasic language, its GFK-0256*, with the last character being the revision level. You can download them from the GE Fanuc website. I don't know of any examples of MegaBasic programs other than the manuals.

If it will help, I can send you a listing of a program I wrote to monitor activity on the serial port, retrieve any data that comes in, extract numeric information from the string, and write it to PLC registers.

BTW, I prefer to keep discussion on the forum so that as many people as possible can participate.
 
Help with PSM script

Steve et al,
I've ordered the PCM card and have been reading the manuals you suggested.
I've attached my first attempt at the bare-bones code. There is no error handling yet as admittedly I need to read those sections some more. If you have suggestions I'd sure like to hear them.

Please shoot holes through this first draft. You'll notice it is not complete relative to the other subroutines however, they will virtually be copies of that listed below.
I don't have a good grip on the NOWAIT command. I'm thinking it is appropriate if I want to handle both com ports in the same script. Any guidance on NOWAIT would be useful.

This application is or should be READ only. We are eavesdropping on a data stream and thus cannot request any data. I only have one shot at the half hour and 24 hour data. If I miss it, or it's corrupted then it's lost. We then have to phone and manually enter the data.

The data packets have an LRC byte attached but I haven't seen any mention of handling LRC in the documentation.

How do I handle BOTH Com Ports in the same script?
 
I'll take a look at your file a little later when I have some time, but to answer a couple of your questions:

Chapter 5, Section 10 of GFK-0255 talks about the NOWAIT commands. When you use them instead of their standard counterparts, the MagaBASIC system executes the command and immediately moves to the next line of the program without waiting for the command to run to completion.

The LRC byte in the datastream is a function of the protocol. It is inserted as a validity check on the data. Both the sender and receiver calculate the LRC using the same algorithm. If the receiver's calculated LRC doesn't match the received LRC, the receiver assumes that the data was corrupted in transmission and sends a NAK character back to the sender to tell it to retransmit the data.

The two ports are independent of each other. You can have both open simultaneously. You may have problems if you're trying to monitor both at 19,200 baud. 9600 baud should be OK.
 
lrc byte

I understand what LRC and CRC are for. I thought a function may already be within the Megabasic. So....I guess I'll create an LRC function.

Port configuration will be 4800,7,E,1,None
 

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