Hello,
I have a strange problem. We have 4 gensets on a oil rig. We use a 4-20 mA signal from a Woodward 2301D speed controller to send the load signal back to a Siemens s7 plc. I connected one of the signals, and it worked out great. 2 wires, powered from the speedcontroller. Set the Siemens analog input card to C on the dip switch. Everything worked, signal was acurate. I am using FC90 analog input in the program.
The I came to the next one, connected it the same way. this time the signal went straight to 32767, when connected to the speed controller. Even when I removed one of the wires it was still 32767. When I removed both, it went to -32768.
I removed the signal and used my loop calibrator. No problem, showed 0 at 4 mA.
The cable between them should be about 20-25 meters.
It seems to be overpressuring the whole signal or something, but I am reading 4 mA in the loop. It is really strange...
Are any of you specialists on 4-20 and knows what this might be??
reg
Andreas
I have a strange problem. We have 4 gensets on a oil rig. We use a 4-20 mA signal from a Woodward 2301D speed controller to send the load signal back to a Siemens s7 plc. I connected one of the signals, and it worked out great. 2 wires, powered from the speedcontroller. Set the Siemens analog input card to C on the dip switch. Everything worked, signal was acurate. I am using FC90 analog input in the program.
The I came to the next one, connected it the same way. this time the signal went straight to 32767, when connected to the speed controller. Even when I removed one of the wires it was still 32767. When I removed both, it went to -32768.
I removed the signal and used my loop calibrator. No problem, showed 0 at 4 mA.
The cable between them should be about 20-25 meters.
It seems to be overpressuring the whole signal or something, but I am reading 4 mA in the loop. It is really strange...
Are any of you specialists on 4-20 and knows what this might be??
reg
Andreas