SLC 5/03 PC Communication

jerry_smith

Member
Join Date
Feb 2004
Posts
21
I am a novice to PLCs. My company has asked me to do this project for them. It involves a SLC 503 and a winXP PC. They have asked me to create a mySql database in the PC and create a serial communication between the PLC and PC. I have with me RSLinx and RSLogix 500. They r not providing me with any other software. I can download mySql from the web. Will these be enough? Do i need a scripting language to make this work?
Now I have connected the SLC and the PC thru a serial cable. I went to RSLinx and tried to configure a DF1 driver. When i press the autoconfigure button, it is unable to do it and asks to check the communication link. I know this cable is good. Is there anything else i have to do to make this work?
I would like someone to guide me on this.
Thank u
js
 
A bunch of questions

1) What flavor of RSLinx do you have? If you've only got Lite, you're up a creek without a leg to stand on (to coin a mixed metaphor). Unless you are planning to write your own driver for this project.

2) Which version of RSLinx do you have? If you're running XP, you should be using 2.40 or better.

3) How do you "know this cable is good"? Has it talked to any SLC on any PC before?

4) Do you have any other way of finding out going on with the SLC? It's possible to change the port settings so that you can't do DF1 communication.

5) Which firmware of SLC 5/03? I think (but don't remember for certain) that the first ones didn't have DF1 communication (like their 5/01 and 5/02 bretheren).
 
The RSLinx verison in my PC is 2.42. I have used this serial cable before and it has worked well.
I too feel that it might be the firmware problem. How can i update it. But should i not be able to talk to the PLC to do the update?
These are the descriptions i find in my PLC. It is
CAT:1747-L532 SER:A
OS#1747-OS302 SER:A

But my serial cable says Null Modem on it. Will that be the source of the problem?


js
 
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No, it's not the firmware. SLC-5/03 controllers have supported DF1 Full Duplex from the RS-232 serial port for 11 years.

A regular null-modem cable should be the correct cable. I use the 1747-CP3 cable.

A previous user of that controller might have reconfigured the serial port to use DH-485 or ASCII protocol. The simplest way to get around this is to empty the SLC memory. Remove the battery and short out the RAM hold-up capacitor at the Vdd and GND pads on the back of the CPU (look in the User Manual for a diagram of how to do this).

It sounds like you are trying to re-invent RSSQL software. This acts as a transaction manager between RSLinx and an ODBC database.

You might take a look at RSSql before you go trying to invent it yourself.
 
I have shorted GND and VBB to get it back to factory settings. Now when i use a AB 1747 PIC to establish communication, i am not able to configure the PIC Communication driver. It says that RSLInx has to be run as an application but is now running as a service. How do i make it run as an application. I went to the services.msc and stopped the RSLinx service and the went to c:\program files\rockwell software\rslinx\rslinx.exe and double clicked it. will that make RSLinx run as an application?

js
 
It's like trying to hit a moving target around here.

You didn't mention the 1747-PIC in your first post, so I gave you instructions for communicating to the Channel 0 serial port.

Now you're trying to use a 1747-PIC. Stop it !

Stick to one approach at a time. Connect from your PC's RS-232 serial port to the RS-232 serial port on the SLC-5/03 controller and use the DF1 Full Duplex driver.
 
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From the RSLinx help files:

"RSLinx now automatically starts as a service, not an application. Running as a service eliminates problems when OPC clients (particularly remote OPC clients) need to start/access RSLinx data. RSLinx can be forced to start as an application by selecting Start > Programs > Rockwell Software > RSLinx > RSLinx Launch Control Panel."


I looked at my version, and seems to be pretty straight forward on forcing to run as an application.

Ken
 
Thanks a lot Ken. I did the same. It works fine now. The Comm Port had been set in user mode in the previous project. I changed it to system mode and now i can see the PLC in the RSWho.
Regarding the other question I would like some suggestion on the feasability of using mySql in a PC and communicate with the PLC serially. The project is to get barcode data from scanners serially to the mySql database and send a control bit to the PLC according to the barcode value. Other than mySql what other software do i need to fetch the scanner data and enter it in the database and to write the control bit from the PC onto a memory location in the PLC?
 
1st make sure that you've got some kind of RSLinx license. RSLinx Lite won't let you talk to your PLC through a non-Rockwell product.
Allen is right about about that.

There are several ways to get the data from RSLinx (once you've got an OEM or Pro license) but since your company won't spring for a low-end SCADA product you can use VB to access the OPC object model in RSLinx.

Do you have VB? Do you have VB programming experience?

Oh yea, almost forgot. This is probably a really goofy way of doing this but if you've got the Professional RSLogix 500 you can use VBA inside of that. It would be easy to program but you'd always have to be on-line with your programming software. If this project is a short-term deal that you'll be taking apart in a month or two you could probably go this route.

Good Luck,

(8{)} ( .)
 

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