Author Topic: T100MD888+ problem  (Read 12194 times)

lemod

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T100MD888+ problem
« on: January 14, 2007, 12:12:44 PM »
Hi,
Is it possible to control some process using PLC without connecting to a PC? I want to use PC only as programmer. My PLC must control device using DAC output. After transmitting program to T100MD888+ and disconnecting rs232, PLC does not respond to change on digital I/Os. When I connect PC to PLC again T100MD888+ works properly.

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Re:T100MD888+ problem
« Reply #1 on: January 14, 2007, 03:47:53 PM »
Of course the PLC is supposed to work standalone without the PC. There is no reason why it only works when RS232 is connected, unless the presence of the RS232 alter the system ground a bit.

Please check your wiring to ensure that when a digital input is turned ON it is indeed connected to the PLC ground (0V) power supply. You can use a multi-meter to measure the voltage at the digital I/O when you turn it ON and OFF. When ON it is supposed to be < 2.5V and when OFF it is pulled up to about 22V for a 24V power supply system.
Email: support@triplc.com
Tel: 1-877-TRI-PLCS

lemod

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Re:T100MD888+ problem
« Reply #2 on: January 15, 2007, 03:40:51 AM »
Everything is working ok now. Thanks