Johnny T
Member
Hi,
I've just got back from a job and have a question that I need to get answers to by tomorrow morning.. eek !
The job I'm working on is upgrading a Series One GE Fanuc PLC system to a S7-312.
So far, so good.. except that the old system had a "T/W Interface" which had a lead coming out of it that went to 12 terminals. The 12 terminals were linked via field wiring to a 00 - 99 switch on the control panel. This switch selects bag length (the machine is a wrapping machine).
When I started the job, I assumed I would be able to just route these 12 terminals to DC Inputs and it would give me a BCD representation of the switch position... nope!
I tried to measure the voltage of these 12 terminals on an identical machine that is running and found that there was no measurement on AC and on DC the voltage fluctuated wildy except for 3 of them.. bear with me here...
The 8 terminals are:
A1, A2, A3, A4, A5, A6
B1, B2, B3, B4, B5, B6
I found that A5, B4 and B6 were a steady 24VDC. The others fluctuated. The switch was set to 2-5 so I thought BINGO! its just binary. Except that I changed the switch to 2-6 and the same terminals were a steady 24. With the switch set to 9-9 none of the terminals are a steady 24V.
Anyone got any idea what's going on with this?
Another question relating to this is.. how would I ascertain what inputs this 00 - 99 switch is altering. Bear in mind that I haven't got the necessaries to go online with GE Fanuc. I have got the old software listing. I sussed out that the inputs are 010 - 117 and the outputs are 020 - 027 and 120 - 127.
Help would be very much appreciated.
Cheers
JT
I've just got back from a job and have a question that I need to get answers to by tomorrow morning.. eek !
The job I'm working on is upgrading a Series One GE Fanuc PLC system to a S7-312.
So far, so good.. except that the old system had a "T/W Interface" which had a lead coming out of it that went to 12 terminals. The 12 terminals were linked via field wiring to a 00 - 99 switch on the control panel. This switch selects bag length (the machine is a wrapping machine).
When I started the job, I assumed I would be able to just route these 12 terminals to DC Inputs and it would give me a BCD representation of the switch position... nope!
I tried to measure the voltage of these 12 terminals on an identical machine that is running and found that there was no measurement on AC and on DC the voltage fluctuated wildy except for 3 of them.. bear with me here...
The 8 terminals are:
A1, A2, A3, A4, A5, A6
B1, B2, B3, B4, B5, B6
I found that A5, B4 and B6 were a steady 24VDC. The others fluctuated. The switch was set to 2-5 so I thought BINGO! its just binary. Except that I changed the switch to 2-6 and the same terminals were a steady 24. With the switch set to 9-9 none of the terminals are a steady 24V.
Anyone got any idea what's going on with this?
Another question relating to this is.. how would I ascertain what inputs this 00 - 99 switch is altering. Bear in mind that I haven't got the necessaries to go online with GE Fanuc. I have got the old software listing. I sussed out that the inputs are 010 - 117 and the outputs are 020 - 027 and 120 - 127.
Help would be very much appreciated.
Cheers
JT