Slc 500 ascii

Hello,

I am trying to use a SLC 5/05 serial port to communicate with an ascii device. The device responds after a command is issued via ascii. It is not clear to me from the AB manual how the AWT and ARL work together. This is basically what i want to do.

Send from SLC serial port ASCII string
:GV

then i want to receive from the device the following ASCII
ACK

Here is what I have so far. B3:0/0 initiates the command.

XIC B3:0/0 AWT 1 ST11:0 R12:0 3
XIC R12:0/13 ARL 1 ST11:1 R12:1 3
XIC B3:0/0 OTU B3:0/0

Is this the correct way to do this?

Thanks!

This may or may not help...

http://www.plctalk.net/qanda/showthread.php?t=21492

It was a 5/04 but the ASCII will be the same

Save yourself time and money call Real Time Automation. They have an ASCII to SLC Ethernet. I did one job with that and will never tie up my serial port again.

I have use 5 of then. They pay for themselves on the first time. Within 10 min. I had 232 ASCII going in and out of my SLC. My time was way more $$$ than the unit cost.

Thanks guys, I got it working. I was using AWT instead of AWA. AWA uses linefeed and carriage return, which is what my (most) device needed.

Here are the two lines of code I used.
XIC B3:1/1 AWA 0 ST20:0 R10:0 2
XIC B3:1/2 ARL 0 ST20:1 R11:0 20

ST20:0 contains GM
ST21:0 contains ACK (read from the device via buffer)

Thanks again

Hey JeffKiper - I'm using one of the RTA Gateways for the first time and I'm also having to learn ladder for the SLC 500 at the same time. Any chance you could share your code for setting one of these up on the PLC side? I'm OK with the device config.
thanks

The device just looks at a tag in the PLC and then transmitts that tag out to the ASCII device.

I ASSuME you are having trouble with the string format. You will need to make sure your string matches what the vendor requires.

Sorry, should have supplied more data. NOOB here and this was my first post. PLC is AB SLC 500 (5/05) and SCADA is GE iFix. It looks like the SLC 500 doesn't use tags but only memory addresses. Gateway is the 435-N700. I'm guessing that I will define a memory address for a String at something like ST10:0 which I would use in place of a tag name. iFix connects thru Industrial Gateway Server (IGS) which is really KEPware. On that side I can have a tag i.e. Scale_250KG_Read.A_CV connected to <SLC 500 IP> Address = ST10:0
See the attached for good example of how some other tags are config in IGS.
I think I should be able to use the String memory for ASCII data output from the 435 and not have to use ASCII memory and do some kind of MOV from A to ST in ladder logic.
To send commands I follow similar logic and have tag Scale_250KG_Cmd.A_CV assigned in IGS at ST10:1 where ST10:1 becomes my tag/address for the 435 PLC to ASCII path.
I'm used to only having to deal with tag names so this memory addressing is kind of new to me.

JeffKiper said:

will never tie up my serial port again..

Click to expand...

I agree save the serial port for programming

Call it the old school back door if you have are network issues..


ProSoft has the MVI4-GSC Generic Serial ASCII Network Interface Module for SLC


I use it to send data to serial printer

works greats

OK lets get back to the basics. What are you trying to communicate to from the PLC. A scale or a SCADA? What does the comunications need to do? Does it need to talk,both ways or just 1 way.

I'm trying to talk to an Ohaus scale with a RS232 port which accepts simple ASCII commands such as "P" for print which will then return a 16 character string i.e.
" 2.54 kg G" with spaces as shown in this case displaying 2.54 kilograms. So comms need to go both ways. The RTA 435 is designed to talk to the AB SLC 500 bi-directional configured both ASCII (device i.e. scale) to PLC and PLC to ASCII. I'm using iFix as my SCADA to connect to the SLC 500 to poll and display the data to the user and to also store that data in a Historian.

Im short on time sorry. The data from the scale will be populated in the ST that you specifies in the RTA configuration. You can use the string to INT or if there is a string to FLOAT. You will nees to play with those. I haven't played with a SLC in years sorry.

This has been helpful. I'll try some things and post the results. Thanks JeffKiper.