rejoe.koshy
Member
hey guys,
I am stuck with a peculiar issue with a micrologix plc unit with an analog input module as an external I/O.
I have a micrologix 1500 series PLC with a 1769-IF4 analog input module which was working fine but recently the analog module started malfunctioning & I replaced it with a new one.After this when I power up , the plc goes in to fault mode (starts blinking red) , but as soon as I switch the key from run to program back to run modes the fault disappears & it starts working.This happens every time I power up.
Added to this when I am running my application , which involves a timer, the PLC goes in to fault mode when the timer stops timing(preset value is reached).
The fault that is displayed in the software is F81- "expansion I/O hardware error"
I am totally confused since the module replaced was identical to the old one.
& the field transducers are working fine.
ps: on careful observation I found a blown transistor in the PCB of the old analog module
I have uploaded the pdf version of the program for your reference
Pls help!!
I am stuck with a peculiar issue with a micrologix plc unit with an analog input module as an external I/O.
I have a micrologix 1500 series PLC with a 1769-IF4 analog input module which was working fine but recently the analog module started malfunctioning & I replaced it with a new one.After this when I power up , the plc goes in to fault mode (starts blinking red) , but as soon as I switch the key from run to program back to run modes the fault disappears & it starts working.This happens every time I power up.
Added to this when I am running my application , which involves a timer, the PLC goes in to fault mode when the timer stops timing(preset value is reached).
The fault that is displayed in the software is F81- "expansion I/O hardware error"
I am totally confused since the module replaced was identical to the old one.
& the field transducers are working fine.
ps: on careful observation I found a blown transistor in the PCB of the old analog module
I have uploaded the pdf version of the program for your reference
Pls help!!