Sending something from 1 plc to another via IP address with 2 SLC500s

[Osborne]

Sending command from 1 plc to another via IP address with 2 SLC500s
and viewing change on 2nd PLC from computer.
I am testing for a job and need to send command from 1 SLC500 to another via IP address. I don't have 2 SLC500s to test with. I need a short program for PLC 1 to send command and PLC 2 to receive command and show change. Trying to use (message) command on both PLCs. Can either turn on input or output or show data register change. Thanks for any help.

 

[kolyur]

I am testing for a job... I don't have 2 SLC500s to test with.

So how exactly are you testing without the equipment?

You need to configure the Ethernet channels on both PLCs, then use the Message instruction (MSG) one on of the PLCs to either write data to the 2nd unit or read data from it. Look up MSG in the RSLogix online help.

 

[Osborne]

Thats part of the problem. I can't test so I need to know before the test the proper way to do this.

How can I trigger the msg command to update of data every 5 sec? Isn't there a command to close a contact repeatedly base on a set time ?
Also Can I send the msg write and msg read to same IP address for testing ?

 

[Bob O]

How can I trigger the msg command to update of data every 5 sec? Isn't there a command to close a contact repeatedly base on a set time ?
Search the help files in RSLogix for TON [Timer-On-Delay]

 

[Osborne]

Sample SLC500 prgs to send and receive with msg command

Can someone send me a sample prg using msg command to send from 1 plc and another 1 to receive on the other plc ? I just can't get the 2nd plc to show the msg received.

 

[Bob O]

I am testing for a job and need to send command from 1 SLC500 to another via IP address. I don't have 2 SLC500s to test with.

I just can't get the 2nd plc to show the msg received.


Do you or don't you have 2 SLC to test with?
Show that you have tried and I am sure someone will step in and help.

 

[Osborne]

No I don't have 2 PLCs to test with. I have allready taken the test six months back and tried for 4 hours. I did the msg write and msg read on plc 2. But could not figure out how to trigger the update and see the change on plc 2. All I have to test with is RSlogic and a ML1100. I have programmed PLCs since the software was DOS base in 1990, but never had a need to talk to another plc. There is a lot more to the test but this is the only part I am having a problem with.

 

[rdrast]

Simply put, you don't use a pair of instructions. It's best, if you just use a MSG READ instruction on the target SLC. The READ has less overhead then a WRITE. Search the forums here on MSG READ SLC perhaps.

To run it cyclically, as mentioned above, just use a free-running 5 second timer.

 

[Osborne]

I thought you had to do both msg write and read

What kind of date can you read ? Counter, timer, bit, etc ? How would you show the data being read ?

 

[Bob O]

The help file has some good information about the MSG instuction Without two controllers, you can't see what has been sent.

I have a little test program for reading and writing values to a DVT camera using a ML1100 that I can post if the MSG setup would help.


Let me know.

 

[ndzied1]

Isn't there a command to close a contact repeatedly base on a set time ?

I have programmed PLCs since the software was DOS base in 1990

I'm thinking I'm misunderstanding something when the same person makes these two statements.

I have allready taken the test six months back and tried for 4 hours.

When is the current test? </SARCASM ON> There are about 4320 hours in six months... </SARCASM OFF>

 

[Osborne]

Test Program

Bob, Can you post test program for me ? Any help would be appreciated.
Thanks

 

[Bob O]

Here you go

 

[Osborne]

Thanks a bunch