Micrologix 1500 Serial Port

[SEBP]

Hi,
I'm trying to send hex strings to a printer via the serial port of my micrologix 1500 but it is not working. I'm not getting any activity on the port when hooked up to the printer, but I am able to see the activity on that same port when I hook up my laptop in hyper terminal to it. In Hyper terminal I see the strings being sent, from the PLC, exactly like I want them to, but it seems like there is missing something when it comes to connecting to another device. I'm using a standard crossover cable when I hook up to my PC but the printer only allows me to hook up Rx, Tx, and GND, do I need all of the other standard serial connector pins hooked up on the PLC for this to work?

Thankyou

 

[bernie_carlton]

You may need to connect RTS (pin 7) to CTS (pin 8) to enable transmission.

Some printers may send a software code (XON XOFF) to suspend communication for a moment. If you have selected ASCII for the port this should be selectable in the setup.

 

[shawn_75]

What printer are you connected to? make/model

 

[SEBP]

Hi,
Thank you for the reply. I'm presently hooked up to a inc.jet printer that is installed directly on the assembly line. It is configured with the following settings: Baud rate 19200, 8 N,1, none, it only has the Rx Tx and ground pins for the serial connection, and I configured the PLC with the same settings and enabled Ascii. The string I'm sending is 02264A6F62312E6A6F6203 with the AWA command, which basically calls a template to be printed. So if I send this command through the serial port of my laptop to the printer everything works, but not with the PLC. I do get the string from the PLC if I connect the serial port directly to my laptop and use Hyperterminal.

 

[bernie_carlton]

Have you made the RTS/CTS connection? If you are using a 1747-CP3 (or equivalent) cable to connect to your PC you are making that connection within the cable.

 

[shawn_75]

That looks like Hex, not ASCII.

Try sending this:

/02 /26 /4A /6F /62 /31 /2E /6A /6F /62 /03

I am not sure if there are supposed to be spaces or possibly some other delineator like a comma.

Shawn

 

[SEBP]

Hi,
The printer doesn't have any RTS CTS pins on the Serial connector. Is there a way to bypass this issue. Can I jump these two pins together?

 

[shawn_75]

I'd bet it isn't anything to do with RTS CTS. If you're sending that as ASCII, here is what your printer is seeing:

30 32 32 36 34 41 36 46 36 32 33 31 32 45 36 41 36 46 36 32 30 33

If you put the slashes in and force the ML1500 to spit that out the serial port as Hex, here is the ASCII equivalent of what the printer will see:

&Job1.job

Shawn

 

[bernie_carlton]

Yes, just connect together the wires from pins 7 and 8 from the Micrologix.

Note - I looked again at the ASCII setup in the Micrologix. If the 'Control Line' says 'No Handshaking' then you can probably ignore the above.

 

[SEBP]

Hi and thanks for your responses. I've checked in the config and I only have the possibility to send data in Ascii. How can I force the PLC to send it in Hex?

 

[SEBP]

Perfect it seems like everything is working by using this string
\02\26\4A\6F\62\31\2E\6A\6F\62\03

Thankyou very much for your help