MD-HMi

[dan]

Hi,

Looks like I need to mount the MD-HMI about 12 feet from the PLC
What is the maximum distance, and what problems may rise ?

Tks,

Dan

[support]

It is not advisable to run the flat ribbon cable for 12 feet. The main problem is that the signals are all TTL level and long unshield cable picks up noise easily and can distort the signal. When this happes At best you get some corrupt characters but if the noise is picked up from the keypad then wrong key sequence may be triggered unless your software specifically filter out input glitches that are caused by noise.

We recommend using an RS485 based HMI such as Maple System OIT or other brands. These are touch panel display and RS485 allows up to 4000 ft of distance between the two devices.

[support]

Another possibility is to use an additional T100MD888+ locally with the MD-HMI and two T100MD+ PLC can then communicate via RS485. This way the control PLC and display PLC can be as far as you want (if you use XServers these two PLC can be in two different countries )