Serial Port Sniffer

[mitsibushiman 0]

Afternoon all!. I'm working on a job at the moment where I have a Mitsi A2SH connected via an A1SJ71UC24-R4 (RS 422 Card) to a personal computer with an laser imaging system for measuring parts. I think there is a problem on the serial line between the PC and PLC. There is an RS232/422 converter in the line and I want to "break into" the serial line and monitor the traffic between the measurement PC and A1SJUC24-R4. Can anyone recommend some suitable software, preferably free? Any hints on any do's or don't would be appreciated also as I'm not entirely "up" on serial comms!. Thanks!

[tragically1969 0]

Which serial line do you want to look at the 485 or 232 ? I always start with a bit of Google Fu to see whats out there: http://www.google.co.uk/search?hl=en&q...fffer&meta=

[mitsibushiman 0]

Thanks for the reply mate. I did a quick google but there seems to be a lot on the market, I was hoping someone could recommend one to save me from some of the inevitable dross that is out there!. I want to look at the signals on the 422 line just before it enters the card!. I want to make sure the Data is reaching the card from the PC. The 422 card is setup for computer link mode using registers D0 and D1 but the value remain at 0 all the time it's as if the serial line is inactive and the PC is not sending the measurement data to the PLC!. This is an existing system that is about 10yrs old that has not worked for the last seven, the manufacturers and installers are all claiming it is to old to be repaired and I've been asked to have a look to see if there's anything I can do!. Any kind of progress from the current fault with is "it doesnae work" is a step in the right direct. Even if it's just a mtter of identifying where the faults lie!. (I think there may be more than one!).

[Crossbow 295]

I used to have to look at data in an RS232 connection, and made a cable with 4 ends. 2 were the ends for the actual serial communications, and the other two brought out just the send line or just the receive line to DB9 receive pin and connected to a laptop running HyperTerminal. This way 2 laptops were looking at each device's send data so I could see the message from one on one laptop and the response from the other on another laptop. Cheap solution as long as you have more than one computer at your disposal, or perhaps several USB to serial adapters.

[Veganic 8]

Free but maybe not what you are after if you want to monitor the RS422 end: http://www.serial-port-monitor.com/

[Supporter 1]

Hi, I use LKA all the time, it's very powerful: http://hem.passagen.se/downloadlka/lka/index.htm //Supporter

[mitsibushiman 0]

Thanks for all the replies guys!. I'm breaking into the RS232 line and and using LKA, it seems the serial card on the PC is faulty. I have another one coming tomorrow from good ol' RS components before 10am tomorrow. Crossbow, thats an excellent suggestion about the four ended lead and hyper terminal, I'll keep that in mind for the future!