Ascii out of a AB 5/03

I'm looking for information on how to use channel 0 on an AB 5/03 for ascii communication.

I simply just want to send a string to a message display.

I've searched the forum and not had any luck finding anything.

Thanks.

Head for the Instruction Set Reference, Publication 1747-RM001, Chapter 10.

The most common instructions are the AWT (ASCII Write) and the AWA (ASCII Write with Append) instructions to send String data types out the serial port.

Generally you set the serial port for "User Mode" before using ASCII commands to send and receive text strings.

The online Instruction Reference includes the ASCII String instructions and the ASCII Serial Port instructions.

Thanks Ken, I glanced through the ascii instructions and went right over the one I needed.

allscott,

Here's a 5/04 with some writing that we used... the example may help, it is a working program... just not the whole thing

Thanks GIT, that helps.

Ok I'm beating my head against the wall over this now. I'm convinced I have everything right but I can't get it to work.

I have a SLC5/03 series C that I am trying to send a two character string out of to a vorne 87/232 serial display.

I have configured the vorne to use terminator only protocol. I wired pin 3 (txd) out of the RS232 port to pin 4(rxd) on the Vorne.

According to the manual all I have to do is send a character followed by a <CR>.

I read the manual ken suggested and figured I shoult use the awa command. I tried AWA with no luck and then tried AWT (as in the example I am posting), still no luck.

Here are screen shots of the channel setups as well as my logic.

ST11:0 contains the string I want to display (42). St11:1 contains <CR>.

I know this is probably something stupid. The RS232 light on the CPU lights up and I don't get an error on the AWT command but the display just sits there.

Any help would be appreciated.

allscott said:

I have configured the vorne to use terminator only protocol. I wired pin 3 (txd) out of the RS232 port to pin 4(rxd) on the Vorne.

Click to expand...

These might be dumb questions, but worth checking:

1) Are you sure that you have the baud/parity/stop & data bits set correctly?

2) Did you wire the GND (pin 5) as well?

jimbo3123 said:

These might be dumb questions, but worth checking:

1) Are you sure that you have the baud/parity/stop & data bits set correctly?

2) Did you wire the GND (pin 5) as well?

Click to expand...

Yes, I've checked those switches several times. All there are for settings are baud, and data bits. There is no setting on the Vorne for parity so I left it at none on the channel config. There isn't a stop bit setting either so I left it at 1.

I've got pin 5 hooked up on the display end only.

allscott said:

Yes, I've checked those switches several times. All there are for settings are baud, and data bits. There is no setting on the Vorne for parity so I left it at none on the channel config. There isn't a stop bit setting either so I left it at 1.

I've got pin 5 hooked up on the display end only.

Click to expand...

It sounds to me like you need to connect pin 5 on the SLC to the gnd pin on the display (pin 5 there as well?)

The two GND pins should be connected together and to nothing else (no earth or power ground), it's just a signal voltage reference that needs to be shared.

jimbo3123 said:

It sounds to me like you need to connect pin 5 on the SLC to the gnd pin on the display (pin 5 there as well?)

The two GND pins should be connected together and to nothing else (no earth or power ground), it's just a signal voltage reference that needs to be shared.

Click to expand...

I'm feeling a little stupid now. The book specifically states not to hook up the gnd cable to an EARTH ground at both ends. I am now assuming that these grounds are both isolated and need to be hooked up.

I'll try it after lunch, Big duh here.

I would subjects you connect all three wires up.

For sure hook up all 3 wires Rx, Tx, Gnd. This is a signal ground and should not be a problem. Generally, shields on long cables should not be connected at both ends but the signal ground needs to be there for serial communications.

Always try swapping the Tx and Rx lines. Even if you are sure you are wired exactly as the documentation says, you have to remember that one side's Tx is the other side's Rx. If the person who wrote the documentation was looking at it from the other side you were, then you'll have it reversed.

Before wrestling with the SLC, see if you can get the display working from your computer with Hyper Terminal or some other terminal emulation software. This will allow you to play with port settings much more easily than through the PLC. Once you can type the characters on your screen in Hyper Terminal and see them come up on the display, you'll be able to use the same port settings in the SLC and know they are right.

I just did an application with a ML1100 and I had to use 1200 baud with the ASCII driver. Don't know if this applies to the 5/03. I also ended up using a null modem to get it to talk to a barcode reader.

In every serial application I suggest you do the following first;

Test the end terminal unit first, for compatibility with HYPERTERMINAL. You can emulate any string directly.

If you want, make a snooping serial cable that you can see the strings that are sent to the screen.



(The cable goes between the two serial devices) and allows you to see the commands that are exchanged between them.

A great piece of software to use to monitor if you have any serial data being transmitted via your computer is http://www.serial-port-monitor.com/index.html there is a free version of the software and it can come in really handy.