Series One PLC (Koyo/DL340) Citect communications RS232

Hi Ben. If you can program the PLC via the COM port using your Tisoft cable, I can't see any reason why Citect should not be able to communicate (access the PLC registers) using the same cable.

What Citect "Port" and "I/O Device" settings are you using??

Cameron:-)

Thanks for your comments Cameron. I've since found out that there are people out there that use Series One and Citect so at least now I know it's possible. Yeah I don't understand why the Tisoft and cables are wired differently either.

I've set everything up according to the Citect help. Comx (is that the Citect port?), Com_Board1(?? I don't have the settings with me), Port

I've also since contacted Citect support and they're looking into it for me.

Ben

Ben, communications can be a bitch at times, i suggest you contact Citect they will be glad to help you.

Yes, it is definitely possible.

I should have asked which version of Citect you were using and what protocol. You should be using the following settings (from the help file):

Baud Rate 38400 (lower baud rates are supported) Data Bits 8 (not configurable) Stop Bits 1 (not configurable) Parity 0 (None)

The v5.42 help file has this to say about the DL340:

---------------------- The DL340 has two communication ports, both of which support the DirectNET protocol. Port 1 (the top port) is recommended because it is easier to configure. You can set the communication parameters for port 1 on the DL340 by use of dip switches on the CPU.

Make sure that you set the following parameters on the DL340 CPU:

n Selectable station address. Set the switch on the front of the CPU to the down position if you want to select an address other than 1. n Station address. This is set by the two rotary switches, SW4 and SW5, on the side of the CPU. The valid address range is from 1 to 90 in hexadecimal (1-5A). n Transfer mode should be HEX. To force this requires the special register, SP1077, to be reset (0). You will need to use DirectSoft to program this register.

n Parity is NONE and cannot be changed. n Baud rate to 38400 as shown here:

NOTE: A number of specialty CPUs are available that are not mentioned here. They generally communicate using a different protocol (such as Modbus or Optomux) and are not supported through this protocol. Contact Citect Support if you wish to use another protocol to communicate.

Hints and Tips

n You will need to turn the power off and on to get your PLC to recognise any changes to communication settings.

---------------------

So - you are using the DirectNET protocol? Your station address will need to be set in the I/O Devices form (use '1' if you can). Use your Tisoft cable.

The Citect guys should be able to help you out. Comms is always a pain - and 38400baud comms is even more of a pain (the high speed makes it next to impossible to see what is really going on).

Good luck!

Cameron:-)

I'm using Citect 5.20 and all the help information is identical to the Citect help you've quoted. Does it say "DL430" on wiring diagram 4 of the DL305 help topic? That has got to be a typo - surely if there was a DL430 it'd be in the DL405 series. And then, assuming that my programming cable is correct for Citect, there are two more mistakes! The TX and RX pins are the wrong way around and CTS and RTS have to be joined.

I spoke to Directlogic yesterday and originally they said the DL340 won't support speeds faster than 9600 but after changing those DIP switches, Directsoft happily talks to the PLC at 38,400.

I have tried both ports. The DIP switches only change the speed of port 1 while port 2 is always 9600.

This last part might be all that is stopping me. I have Tisoft and only the demo version of Directsoft 4 - neither can adjust SP1077 as far as I know. Directlogic have never heard of a "SP1077" but they do know about a C1077 (control relay). By default this relay should be off which enables HEX communication and not ASCII. Directsoft demo version is detecting hex communication so I'm assuming that this isn't the problem.

It sure is a pain! I'm inclined to go back to square-one and not trust any of Citect, even if I have to use 2 bits per minute :)

Citect's only suggestion other than SP1077 has been to link SG to the screw in the 9-pin plug. I wouldn't have thought this would be the difference betwen success or failure, maybe it would solve an intermittant problem.

When I try to use Citect with the Tisoft cable at 9600 in port 1 the TX/RX briefly blink once every 20 seconds or so, obviously just to tease me into thinking I'm getting close.

Thanks for your help guys but don't feel obligated to spend anymore time on this. It's Citect's responsibility now.

Ben

No.. not really. Citect refer to it as the "DL305 series". IMHO, it's the same driver so they don't bother to amend the name just to keep the manufacturer happy - the Citect people have better things to do.

Again, it depends on exactly how you are connecting it. What you have mentioned (the Tx/Rx wrong way and CTS/RTS joined) is known as a "null modem" connection - the correct one for a hard-wired cable.

What the Citect Help has described is the connections for use over a modem link. Perhaps they didn't explain it clearly, but it's not really a big deal (compared to totally incorrrect pin numbers, for example :-)

Now *that* is a mistake.. Typical sales people! ;-)

That explains the "easier to configure" understatement.. :-)

A hex/ascii mixup will certainly stuff you up. I suggest checking this for sure - even if you have to borrow a Real copy of Directsoft to do it.

Citect is not the problem, believe me. (Disclaimer: I don't work for Citect!)

If you can't use Citect, you won't be able to use anything else either. I'd chuck the PLC out first and buy a real one! ;-) (Hint: Anything else you buy will be using the same method (protocol) to talk to the PLC.)

Do you have separate Tx/Rx lights? (If not, try inserting a break-out box that has separate lights in your connection)

If you are getting the Rx light flashing every 20 seconds or so, that will be Citect sending the request down. If you don't get the Tx light pretty quickly after, then the PLC doesn't understand the data. If you get both flashing then Citect doesn't understand the PLC's message and you should get a different alarm on the Hardware Alarms page (not "I/O Server Off-line").

It certainly is.. Keep us posted :-)

Cameron:-)