Rajan

[Rajan]

Hello Experts  I am facing problem with CJ Series Analog I/O module MAD32. The Run LED is Lit, ERC Led is also Lit. what could be the reason?

[Mendon Systems]

The ERC light normally indicates an open or out of range connection to a current loop device.

[Rajan]

Tahnk you Mendon Systems for the reply  

The two current inputs of the module are connected to analog output terminals of two indicators. The sticker on the indicators show that the analog output is 4-20mA. When the two inputs are connected, the HMI display for the analog signals becomes unstable (changes rapidly)

[Mendon Systems]

I would suspect that the power supply to one (or both) indicators has become erratic.

[Rajan]

The power supply to the indicators is 220VAC, both are powered up and working correctly

[Mendon Systems]

Obviously something is not working correctly.

The ERC indicator on that module will come on whenever the voltage on an input set for 1-5vdc (or 4-20ma) is not in a range between 1 and 5 volts. The erratic readings you are seeing would indicate that there is something other than DC voltage on those input signals.

[Rajan]

Dear Sir

I have set the all the input selector DIP switches for Voltage. In this condition the module should not detect a disconnection, right?  Still the ERC indicator is Lit

[Mendon Systems]

The ERC detecton works when any of the four ports is set to 1-5 volts (also 4-20ma). There is only one ERC indicator so an out of range condition on any one of the ports that is set to 1-5 volts will trip the indicator.

The function of the Dip switch is to connect a 250 ohm load across the input terminals for current loop inputs. Opening the switch with a current input connected would probably cause an ERC condition.

Read section 9 of the W345 manual.