Slow response via GSM

[stembera 4]

Hello world,

Everytime I have my system connected to Remote Access via GSM modem, I face the problem of slow response from the remote site. Even if I use an URC compiled file, first display appears after two or three minutes after establishing connection. I tried to create very simple display with only a few objects but the response time was the same. I experienced extreme situation with application in area with weak GSM signal - modems connected but the first display did not appear at all. I tried it many times without success.

Do have somebody some similar experience with modem connection? Is there some way to increase speed of display refresh?

(Hardware: V570 / Cinterion MC35i Terminal)

[Simon 47]

In my experience, remote access via GSM modem for the colour PLCs is quite slow. Possibly the response may be slightly faster using Remote Operator instead of Remote Access. However the fundamental problem is that the baud rate via GSM is only 9600. The ideal solution is to use a broadband wireless modem connected to the PLC via ethernet. If you are stuck with the GSM serial modem, another option may be to use SCADA software and Modbus.

[Saragani 145]

In my experience, remote access via GSM modem for the colour PLCs is quite slow. Possibly the response may be slightly faster using Remote Operator instead of Remote Access. However the fundamental problem is that the baud rate via GSM is only 9600. The ideal solution is to use a broadband wireless modem connected to the PLC via ethernet. If you are stuck with the GSM serial modem, another option may be to use SCADA software and Modbus.

Another problem is that the communication is being done with smaller chunks (Something like 8 times smaller) which requires more packets to be sent and received, and there is more overhead and more time that is being wasted on the communication "handshakes".