Sending data to printer over TCP

I have had a look at some other topics involving setting up a TCP connection, and have managed to send some data to a label printer successfully.

Just trying to figure out the best and most reliable way to do it.

Some background:
Printer is an Intermec PD43 label printer.
Using IPL commands to send data / commands to printer.

I have tried the following two methods:

1) Purely using Python scripting
Unfortunately I cant figure out why sometimes it works and sometimes it doesn’t (with no indication of an error).


def printLogLabels(data):
    # data - pyList of serial numbers to print. ie: [1000000321, 1000000123]

 	import socket
	import sys
	scriptName = 'shared.production.printLogLabels '
	log = system.util.getLogger("Script Debugger")

	tcp_ip = ''
	tcp_port = 9101

		s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
		s.connect((tcp_ip, tcp_port))
		# Loop through data list and send print command for each serial number
		for item in data:
			MESSAGE = "<STX><ESC><E2<CAN><ETX><STX><ESC>F1<LF>" + str(item) + "<ETX><STX><ETB><ETX>"
			print MESSAGE
		# end for

		return True

		shared.log.scriptError(scriptName + str(sys.exc_info()[1]))	
		return False	
	# end try
# end def

I’m wondering if there is some issue with socket connection that i need to check the status of somehow.
I read in an earlier topic that changing the tcp port and back again worked, which i have had some success with.

2) Ignition TCP Driver
I have also looked at using the Ignition TCP Driver to do the same thing, and have had some pretty good success with that.
I’ve been writing directly to the TCP Driver tag using:

		for item in data:
			message = "<STX><ESC><E2<CAN><ETX><STX><ESC>F1<LF>" + str(item) + "<ETX><STX><ETB><ETX>"
			system.tag.write("Gisborne01/ProdSystems/IntermecPD43/Writable", message)
		# end for
		return True
		shared.log.scriptError(scriptName + str(sys.exc_info()[1]))	
		return False	
	# end try

Is it better practise to use the method mentioned in this post when writing to TCP driver tags?
Should I be clearing the tag myself after every write? Seems like i don’t have to.

Also how can i detect errors with the connection? I don’t think i can use the Inactivity Timeout because i’m never actually receiving data from the source.
Pulling the Ethernet cable doesn’t seem to affect tag quality or device status.


Were you successful in communicating with the PD43 printer?


Yes i got it working by using method #2 above.
Interesting timing though, as we’ve just started having issues with the printer not working after several years of no problems. So trying to work through that now…

The main problem i’m finding with the method #2 is that there is no real confirmation that the packet was received, and no real errors if things go wrong.

How are you mapping the writable tag for TCP driver? I am little confused here the only tags that I find in browse are Last Receive Time and Message under 9100 and Diagnostics

I have got that figured out…thanks