I7018

[can]

Hi. Can I just use I7018 with MD888 by loading the program example and connect with a J type thermocouple?

[support]

Yes. Look for sample program in the samples\I-7000 folder.

[can]

Hi. do I need to do any calibration?

[support]

I-70xx has calibration procedure mentioned in their manual. I believe they are calibrated by the factory but if you think the reading is not consistent with your in house standard measurement then you can follow their procedure to perform calibration.

[can]

Hi.

1) I7018 works perfect with MD888 when I'm connected to MD888 using RS232 but not RS485. Why?

2) Can I use I7018 on a 1s clock pulse to monitor the current temperature and at the same time use readmodbus to read the dm on another MD888 on a 1s clock pulse? How?

[support]

I-7018 only has RS485 interface. No RS232 interface so I don't understand how you connect RS232 from T100MD to I-7018?

It is recommended that you only connect RS485 devices on the same bus. If you connect I-7018 and another T100MD888+ both on the same RS485 bus, and you switch the command from MD888+ to I-7018, it may not work. There is no guarantee. The I-7018 may misinterpret a data meant for the T100MD888+ and thinking that it is a command. It could then change some parameters and cause you problem. We don't recommend it.

[can]

Hi. I'm confused. What does connecting them on the same bus mean? Can I connect 2 MD888 and a I7018 together using RS485? 1 MD888 will be the master giving the readmodbus and writemodbus command while 1 MD888 and I7018 will be slaves. Should work right?

Thanks

[support]

I-70xx uses only straight ASCII command without error checking. If you use READMODBUS and WRITEMODBUS RTU commands you are sending binary Modbus protocol via the network and there will be binary modbus data that the I-70xx could interpret as command for itself (wrongly, of course) and therefore lead to unknown consequence.

If you must use them together this way, you may be better off using the NETCMD$ command to communicate between the PLCs, or use the MODBUS ASCII command so that there is no binary data that could corrupt the I-70xx.

One possibility you can try is to run the I-70xx and the PLC in different baud rate. Then you must use the SETBAUD command to change the baud rate every time you switch communicating from one device to another.  

But we would like to state again that communicating over the same bus using two different protocols is NOT recommended, but you can try it if you must and check if it can work for you.

[can]

Hi. Will there be any difference between using modbus and modbus RTU with I7018? As for using I7018 and MD888 on the same bus, setting different ID will not help?

[support]

I-7018 DOES NOT support Modbus ASCII or Modbus RTU protocol.

As explained previously. They are different protocols. We can't tell you definitely works or don't work. We recommend against running two different protocols on the same RS485 bus. But if you choose to do it then you have to thoroughly test it to make sure it works.

Maybe you can consider a F2424 or F1616-BA which has TWO RS485 ports. You can then connect the I-70xx to one of the RS485 port and the slave PLC on a different port. That should work well.

[can]

Thanks for clearing the air on the I7018 part. So in order to make the whole system work, I should use netcmd$ by the Master MD888 to read data from other MD888 and I7018 or write to other MD888 and I7018?

[support]

That's what you can try. Again since you are running two different protocols but both are ASCII so there is less risk of unintended data being misinterpreted by I-70xx. But do TEST IT THOROUGHLY. You can let us know if it works for you.

[can]

Hi. I'm currently using modbus ascii to communicate between a master MD888 with a slave MD888 and at the same time using Netcmd$ command to communicate between the Master MD888 and the I7018. They are working fine from the Online monitoring. However, when I use excellink to retrieve the temperature readings, the networking fail. Excellink goes into suspension mode and online monitoring is closed and unable to find the master plc. Why is that so?

How do I use netcmd$ to write a value inside master dm[5] to slave dm[60]? z$=netcmd$(3,"@03wvd0005?)
where 03 is the slave id. what should the ? be? Thanks.

Regards

[support]

Note that host link command is case sensitive. WVD is upper case only. Please refer to the manual for explanation of the parameter of WVD. Best way is to experiment it yourself.

Your ExcelLink may have asked TLServer to access wrong data or wrong PLC ID. That may have caused the TLServer to try to talk to a non-existent PLC and it slows down completely and the networking with it failed. When properly setup it should work. Try it with a simplest command first.

[can]

Hi. You guys really know your stuff well. The error is due to wrong ID in the excellink. Once the ID is corrected, it works fine now. Thanks.