I/O ERROR in CPM1A(CPU30)

[rbbalaji 0]

Hi Jay, I was rebuilding an old fixture and I have encountered this strange problem. When I connected the sensors, the sensors were showing weird signals. That is part present if no part is present, when I used the ground in the DC power supply(AC to DC). I was frustrated and removed the ground and added a DIODE acreoss the output and all seemed well. Until this morning when I turned the system ON I encountered this ERROR in the PLC and when I connected the hand held it showed an I/O ERROR. Then I turned the system ON and OFF several times until the ERROR disappeared. And now after everything seemed fine I was just testing the fixture this evening and after about 20 trials this problem occurred again. And I turned the system ON and OFF but it was of no use until I pulled out the pressure. Then I turned it ON it is fine now. But I am worried that this should not occur during production time. What should I do. By the way the input is 24VDC and two of my utputs are 24VDC and one is 110VAC. Thanks, Balaji

[Guest Moty Donner]

Hi I experienced once wierd sensors signals, and found that the probleb was using the CPM1A 24VDC supply. For sensors that need power supply (usually 4-20mA) you may have to use and external power supply. This avoids supply overload and noices. Moty