A1S to SCADA via onboard C24 interface

[garypeme 0]

Hi I am having real problems getting the above to work. Cable appears to be ok, code to manage c24 part of program. Does anybody have any suggestions and/or general tips for dealing with these interfaces? Thanks in advance Gary

[panic mode 246]

Ok, here it goes: - provide full part numbers (which C24? there are so many of serial cards and they all have C24) - provide SCADA name and version, what protocol you want to use (ASCII?) - what port settings we are talking about (bps, data bits, ...) - what cable (part number or pinout) and is this going to real COM port or maybe USB<>RS232 converter - what is the cable length? (you cannot do 115kbps or RS232 and have cable 100m long). - are you sure PC side serial port is working as expected (loopback check etc.) - is the serial card working correctly (loop back check, LEDs status, status bits, error codes) - everything else you can come up with but this would be good start.

[garypeme 0]

Panic Mode, thanks for your reply... 1. PLC has onboard C24 interface. Part number is A1SCPUC24-R2. 2. iFix 3.5 via 232. 3. 9600/8/1/no parity/no flow control. 4. Standard DB9 caable. 5. 5m. 6. Yes. 7. It appears to fail the loop back self test indicating it has failed the 232 comms check. 8. I have code in the PLC to handle the C24 interface. Is this required. I have the mode thumb wheel set to protocol 1, is this correct, and what is protocol 1. There are also options for protocol 2, 3 and 4. Your help is much appreciated

[Colin Carpenter 10]

Hi Gary, If you get the darn thing working, I'd like to know how you did it. I've been scratching my head trying to get a UC24 to act as a second programming port on an A1S system (the CPU port will be taken up by a Mac screen which is too far away from the PLC for me to transparently talk through the MAc via serial). The only cards I've used for SCADA acces have been the RS485 versions, which tend to be easier as the RS232 lead and connections is sorted out in the RS232 - RS485 converter, and from there onwards, the wiring is much simpler. The manuals for the UC24 set a new standard in lack of information in my humble opinion........ five protocols, but not a single word on what each one is used for

[panic mode 246]

Did you guys check this post (it's a bit older) http://forums.mrplc.com/index.php?showtopic=518 I will see if I can dig out anything else, but it will have to wait, I am tied up at the moment.

[andybr 5]

Gary I have used these cards to connect to SCADA systems and for programming on many occasions and have never had a problem. When I have seen others have problems the issue has almost always been with the cable. This needs to be a null modem cable and the handshaking pins MUST be linked together as shown in the A1sJ71C24 manual. The last requirement is nearly aways the problem. I am sorry I cannot give you the pinout but I do not have a manual close at hand. You should not need any PLC code to get the card to work with iFix. Andybr

[garypeme 0]

Hi Guys Update of my progress today... Still not managed to achieve successful comms via modem (sorry I didn't mention this in my original post), but i can get comms if i connect directly to my laptop running the Fix DB using the cable as detailed in the manual and by andybr. FYI Colin i have set the anoumous protocol switch to mode 1, just a guess but it appears to work. Also as mentioned here no PLC code required. To clarify the required system... A1S PLC <----- 9 Pin - 25 Pin Serial Cable <------- Racal 3223 Modem --- 4 Wire LL --- Racal 3223 Modem <---- PC running iFix (MIT driver) I have verified all cables involved and they are ok. iFix Driver configured correctly with correct com ports etc. The modems are dialling and connected to one another (CD indication on), the SD and TD lights flash iFix end but nothing PLC end. LL has been verified by telecoms company but this is all I can think is causing the problem? Thanks for all your feedback thus far

[FNMdeJong 7]

Since there are several questions accross each other. Please take a look at the manual for the GX developer software. Section 16.2.3. Setting method for communications through C24. It seems to me that you're cable is not the correct one and that the parity settings is not correct. For the pin layout of the cable, try the next thing: both sides connect 1,7 & 8 together, 4 & 6 together. pin 5 on pin 5. Pin 2 on pin 3 and pin 3 on pin 2.

[Colin Carpenter 10]

Hi Gary, Can you confirm which of the 3 wiring methods shown in the manual that you use in your cable? I've attached the three options in the graphic below .... currently I've got the cable made up as shown in option B, because I have no idea if a laptop serial port is capable of turning on or off a CD signal. I chose this option after reading Panic Mode's post in one of the other threads. Cable seems to "sort of" work .... light flashes on the UC24, then other lights come on, but no real comms. Cheers.

[garypeme 0]

Hi Guys Sorry I haven't got back to you sooner. Colin, I have wired the cable kind of like option A but the connection required for the modem I am using is a 25 pin type. Anyway comms are successfully working now. There were two problems... 1. One of the leased line wires was open circuit. 2. Modem wasn't correctly configured. Thanks for all your help