rslinx communication error:

[szimmer]

Hello,

Our company bought some basic PLC equipment and RSLogix5000 software to learn how to program PLCS.

The specs are below:
Hardware:
Allen-Bradley Company
Logix5555 Processor with 750Kbyte MEmory
1756-L55M12
1756-L55/A 1756-M12/A LOGIX5555
16.21

Software:
RSLogix5000
V16.03

Computer:
HP
Intel Core2 Duo
2.00GHz
2GB of RAM
Windows XP Pro with SP2 installed

Problem:
I have written a very simple one rung program (on and off button) to test out the PLC in Run mode. However, when I go online, there is quite a long delay. It almost seems as if the program is crashing. Finally it goes online but the software runs very slow. After awhile I get the error:

806-8004-2535
Can’t communicate with RsLinx
RSLogix5000 has been taken offline.

Being new to this topic, I am not sure if the issue is the software, controller or cable? It is important to point out that the cable from the controller to the computer is connected via a serial adapter to USB connector. Could that be a possible issue?

Any suggestions on how to trouble shoot this problem?

Any tips would be appreciated. And if you need more information to analysis the problem better, please let me know.
Thanks,

Simon

 

[controlsdude]

I see your L55 is at the right firmware. Now is your RSLinx at the right revision level?
Should be this level!
Ver: 2.51.00.
Build: 21 (CPR7)

Check on the help , about?

If your USB cable to serial is shown in the Hardware config as a Com port then you should be ok.

Did you do an auto config under Rslinx for the DF1 driver?

 

[szimmer]

Thanks for the quick reply.

The RSlinx communication is:

2.52.00.17 (CPR9)

Is this okay?

The COM port for the serial to usb does show up fine in the hardware setup so I think you are right, it is okay.

I did do the auto config setup and that worked fine too.

In general the connection works but it is extremely slow and often crashes.

Any ideas?

thanks again,

Simon

 

[controlsdude]

sorry

its at least that rev level which is RSLinx has to be at
Ver: 2.51.00.
Build: 21 (CPR7)
or higher

you do not have hardware handshaking still on on com port?

set handshaking to none

The default on plc rs232 is 19200,8N1, no handshake.

The other strange problems I have run across is the setting of the station number that is different than your processor under the DF-1 driver. You do not think the USB RS232 is changing this station number on the fly?

 

[szimmer]

Hello,

Sorry but the handshaking is not clear to me.

One thing I noticed is in the hardware setup, the USB Com Port is setup as:

Bits per second 9600
Data bits 8
Parity None
Stop bits 1
Flow Control None

However when i configure the port in RsLinx it is set at 19200. Should it be 9600 also?

Is that right.

Otherwise, where can I set the handshaking?

Could you explain more about the station number issue? I did not quite understand that either.

Thanks again for your help.

Simon

 

[szimmer]

By the way, station number is set 00.

Not sure if that changes.

Simon

 

[controlsdude]

Station number problem: If for some reason the station number on processor changes to something other than default. Just change your RSLinx station number to something other than 00 or 01.

RSLinx just changes the settings on your com port nothing to worry about. no matter what the com settings say on the Hardware device manager.

Should work?

 

[szimmer]

Hi,

I got it to work by not using the serial cable and just doing it via ethernet module. MUCH BETTER performance.

Thanks for the support though.

I am sure I will have more questions in the future.

Take care,

Simon