BobB

Have not used a CQM1 for quite a while now. Have replaced this PLC with the low end processor from the CJ1 range (CJ1M-CPU12). A lot more functions to work with and make life easier for programming. Unfortunately I am unable to assist with Modbus TCP. Have not used it or even investigated the protocol structure at this stage.

Looks very much like homework does it not? Have a look at using shift registers.

Thanks Sleepy. The project is one I am quoting at the moment and the CJ would certainly make life easier, and less expensive. Oh well, looks like the CS1 is the only way I can go.

Here is a link to the Omron US website manuals. You will find what you require there. Omron Manuals

Refer you to this thread UM Protected

You can use either CX-Programmer or Syswin. Syswin supports many of the older PLC's but CX-Programmer does not support some of the older ones. On the other hand, CX supports all the latest PLC's while Syswin does not. Talk to your local Omron distributor and buy the software.

Have you tried MOV DMxxxx to a register after the ASCII string and then including it in the length of the SEND command?

Here is a good place to start for fieldbusses Fieldbus Page Other network information can be found at any PLC manufacturers site.

To the serial port. You can set the serial port and screen to host link mode or NT link. Either will work. Unplugging will not affect the CPU but not recommended. Unpluging and plugging in to active serial ports can do some terrible things to the comms chip. Been there, done that, and had to pay the price of having the chip replaced, SEVERAL TIMES!!!!

Transfer is function 70 in most PLCs. If someone is pushing a button it may be advisable to use @xfer so that the transfer only happens once when the button is pushed and not every scan.

Go here Omron Manuals and look for the manual. The website was down when I tried to get you the manual address. The RM201 communicates with an RT201 on a rack. You can place analogue cards on the rack. Just watch out for total load on the rack as per the manual. Analogues are special cards that need an individual address by ritary switch on the unit. Maximum special cards per PLC is 10 for the C200H.

Documenting the contacts is really quite easy. I have set CX up so that when I am in the symbol editor, and I only use global symbols, Alt S inserts a new symbol, although I tend to use Ctrl C and Ctrl V a lot and then modify the symbol and description. The other way is to copy and paste in and out of Excel. Works a treat and when you copy back into CX, if you make a mistake, CX will not import the defective part but will give you the option to modfy the symbol/bit number. Most of the time I document my I/O (real I/O) before I start writing the progam. Most of the internal bits I document on the fly. Documentation is not different from 3.0 to 3.2 but the big advantage is that when inserting a function you can do it in one line of text instead of fiddling about. For example, bitcount, call up function and type in"BCNT #2 130 D1000" will bitcount 2 channels starting at channel 130 and place the result in D1000. Beats the hell out of getting RSI from dropping and dragging the european rubbish. If you know what you are doing, that little feature can save an enormous amount of time. Also, set your PLC up to "auto detect baud rate" at 115k. Man it is fast.

ArikBY I felt the same way about Syswin vs CX-Programmer. I have now changed my mind completely. There are a couple of things Syswin does better, when online programming after finishing your edit the page down key loaded the chages into the PLC and moved to the next rung. A little easier than ctrl - sft - E. Setting up simple Controller Link networks was easier in Syswin as you did not have to go away to CX-Server to set up a simple network. If working with networks all the time, CX-Server is far better and more powerful than the simple set up in Syswin. Also, Syswin had the ability to delete a scrambled rung from a running PLC programme, CX-Programmer does not. I was working on a job with an early version of CX and Citect running on the same computer. 9 PLCs networked together in a power station. I was working on the program in the master PLC, which could not be turned off or the power station would black out. I was doing online program changes and a couple of rungs that were downloaded became scrambled (incorrect syntax). I am not sure if this was a combination of CX and Citect running at the same time or not. CX would not let me delete the scrambled rungs. I had Syswin on my laptop, hooked up to the programming port on the old C200HS, uploaded, found the scrambled rungs and deleted them without a blackout or problem. Thats about the only benefits quite frankly. CX is so much more powerful, configurable and easy to use once you take the time to learn how to use it to your advantage. There are so many good things, auto connect, auto baud rate detection at 115k, multiple PLCs up and monitoring at the same time on a network, the ability to have PLC bits words etc from 4, 5, 6 PLCs in the watch window at once, the ability to monitor 4 words in binary at once, etc etc. One could go on for days. The bit monitor in V3.2 is far superior to earlier versions but still does not come up to the old CAPS programme. Setting up a monitor table there was brilliant, the best I have ever seen in PLC software. You could just type in timers (PV, bit and set value all in the one line), bits, words in any format (binary, ASCII, hex etc). You could even monitor a word in all formats at once by entering it into the table several times and monitoring each entry in a different word format. It was like a big spreadsheet at the end of the day. That is one area where CX, and any other PLC software I have ever used, could really be improved. Anyone who used CAPS extensively I am sure will agree with me about the CAPS monitoring system. Come on Omron software writers, and everybody else producing PLC programming software, get an old copy of CAPS, hook it up to an old PLC and see how GREAT the monitor was. A spreadsheet type monitor similar to that used in BMS systems and FIX Dynamics (about the only thing I like about FIX) where you can click on the mouse each time you wish to refresh your readings would also be fantastic but the ability to turn on and off constant monitoring would make it even better. How do you go with Syswin and CS1 and CJ1 processors? Syswin does not support them or the extended instruction set, without which I would be lost these days. I go back to an old C200H, HS or even Alpha and cannot find the instructions I use these days with the CS1 and CJ1. ArikBY, take the time to learn to use CX-Programmer properly and to your benefit and you will never want to go back.

If your PLC has a host link port and a serial port, each can be set up to have different addresses in CX-Programmer or Syswin. If there is only a host link port, change the address, disconnect, power the PLC down and up again and then change the address of the PLC in Syswin or CX-Programmer. CX-Programmer - address can be changed by right click on the PLC and selsct properties. Syswin - address can be changed by selecting Project/Communications.

You can find manuals for everything hereOmron US Website

Try this. Omron Host Link Manual

It looks like a C20P or C20H. Check the type against these numbers.

Jay has already answered you on plcs.net with respect to the software. CX-Programmer only runs on Windows. I use XP and find it OK but any flavour of Windows from (preferably) 98SE up will be OK. Have no tried it on straight 98 or 95.

Generally, cannot see how you could do that. However, if your 2 devices were Modbus RTU protocol for example, these devices have an address and you could write a programme to extract data from each address in turn. Although, multidrop Modbus RTU is normally RS485. Use a 232/485 converter. If the devices do not have an address, I cannot see how you could do it. Maybe someone smarter than me will have a different idea. I would use the SCB. Good luck.

Here is a link to the CQM1H serial communications board manual. CQM1H serial communications board

Should not be too difficult. Use RTD/4-20ma transducers, preferably isolated types, into your analogue inputs. Scale the inputs to present the data in real BCD, x+y and divide by two.

Have you setup the serial port in the PLC to NTLink? Default is host link.

It definately works with the CJ. I am using it with a CJ1M. I believe 1.3 is the latest version. Have you updated your CX-Server? The latest I have is V1.7.

Are your outputs turning on? If so, are the being read as inputs in the other PLCs? It may be a wiring problem. Check that out first by forcing a few bits to see if the inputs are turning on in the other PLCs.

Depends what you are looking for. Pretty hard to define cheap as this is relative. No good having cheap hardware with lousy software and a lousy instruction set. Check this out. It is the new CJ1, very small, powerful and a lot of useful functions (huge function list). Omron CJ1 Leaflet