1734-232ASC Delayed Characters in String

Hi All,

I have an annoying issue with PointIO ascii modules sending a string of characters to an OEM printer.

There are 120 characters to the string that are being sent from the 1734-ASC/C module to the OEM printer at 19200 8N1.

The issue is that there is a time delay between character (observed with scope) e.g. A...........B.....CDE...F etc not ABCDEF.
The delay adds up to over 200ms and the OEM printer PLC gets only a protion of the complete string. (It will timeout after 200ms).

So the complete path of the string uses this hardware:
1756-L61 PLC -> 1756-CNB/D Card -> 1734-ACNR/A PointIO -> 1734-ASC/C -> OEM Printer PLC (Unitronics)

There are two separate sister setups (ie two PiontIO modules and two printers) receiving strings from the same PLC (above). The exact the same issue is on both.


I've repower, reseated the 232 modules and repowered the PointIO but not changes.
I've checked the setup of the modules as best I know how (FYI I'm no expert).


Has anyone seen delays in strings before?
Is it setup of the module somehow?
How could this be narrowed down?

It'd be great to get some feedback.
Thanks in advance.

james it's a long time since I worked on ASCII strings to printers and I don't have the information to hand so I could easily be wrong but I seem to remember the string character length was 84 . It may be worth checking this out with the set-up you've got . Sorry I can't be of more help .

Regards , Paul

Welcome to the Forum !

Have a look at the size of the I/O connection across ControlNet to the 1734-232ASC.

I'll bet that it's smaller than the whole 120 byte string, and that the logic is somehow sending just a few characters at a time.

I don't think this could be a handshaking issue... my recollection is that the 232ASC doesn't support anything but Tx/Rx/Common.

Thanks pal, I had to check the module manual and is states Max No. of Tx Chars is 1-128. So should be in range, great idea to check though. Thanks

Ken, thanks for your comments also.
It could well be an issue with the programming and that's where I'm focusing on right now.

Cheers