GE Fanuc 90-30 PLC & RS232 PC to PLC Comms

[qee]

Hello all,

I need to talk to a GE 90-30 series PLC using the RS232 protocol. I need to be able to send data strings in the following format to the PLC via RS232 from a PC:

stx <Data> etx

Is this easy enough to do?

I'm OK with the PC side of things but I'm unsure of how this will be achieved in the PLC. For example, is this possible through the RS232 port of the PLC? and if so how do I “see” or access the data in the PLC?

What I need to do ultimately is fire different PLC outputs depending on the data value received. Again I'm OK with this, it's getting and comparing the data in the PLC that's the problem.

Any help would be greatly appreciated.

Thanks, AJ

[Steve Bailey]

RS232 is not a communications protocol, it is an electrical standard.

The serial port on the 90-30 power supply is RS485. You can communicate with it using GE Fanuc's SNPX protocol.

Some 90-30 CPU models have additional serial ports. These may be either RS232 or RS485. They can be configured for SNPX, RTU, or CCM protocols.

[qee]

Thanks Steve for your quick reply.

I'm trying to find out the exact PLC CPU type.
So far the only info I have is that the available ports are RS232, RS485 and Line SNP?

The PC application uses the "TDVCmdProtocol", which apparently is a simple text type.

E.g. stx <Data> etx

I will post any more info when I get it.
Many thanks for your help so far.

AJ

[Tom Jenkins]

Hey, Steve, I love your atavar! It is amazing how few people understand that basic business equation.

[qee]

It's a GE Fanuc 90-30 350 CPU.
The PC application can communicate via RS232, Profibus or TCP/IP.

Does anyone know how we can talk to it?

Thanks
AJ

[Tom Jenkins]

You should probably get your local vendor for the PLC and for your PC software.

RS-232 and the related RS-485 are electrical standards for serial communications. EtherNet is an electrical and message packet framing standard. There are hundreds of devices that meet RS232 standards that cannot talk to each other, and there are hundreds of EtherNet devices that can't talk to each other.

A protocol is a format for a message or data communications exchange that defines things like addressing, error checking, data request and response codes, data format, message length, and so on. The same protocol can be used on RS232, or RS-485, or even embedded in EtherNet packets. TCP/IP is one type of message packet format.

Both devices in a communications link must be using the same communications electrical standard and the same protocol to communicate.

The 90-30 Model 350 supports SNP and SNPX (System Ninety Protocols) and Modbus RTU. It also supports ethernet, but I'm not sure of the protocol used. There are also Genius and CCM protocols that you probably won't want to use.

It is probable that Modbus RTU is the easiest for you to implement and is probably available as a canned protocol with your PC software, but you have to check. If not, the Modbus RTU protocol is published and you could write your own or obtain a third party package.

This is a non-trivial task, and it may be beyond the scope of a forum like this to give you the training you need to accomplish it. That is why you need to do some research and vendor contact. If you do a search on this site for some of the key words used above you will find lots of reference material.

[qee]

Thanks Tom for your help.
Much appreciated.

AJ

[louzar]

Hi Tom
i am a student in computer inginiering and i must implement an application that program tsx17 20 whith pl7_1 language .
so if you have any documentation about the protocole betwen tsx17 and pc please send me it .this is my email nizarellouze@yahoo.fr