Output Problem

[cgiltrow]

Hi,

I have a Comfort I system.

I have an output (Output 9) on an LEM (8 input /8 output) connected to the main motherboard.  I use this output to open and close my gate by pulsing a relay.  This was working well.

Now it works sometimes and sometimes not.  If I reset the system this helps sometimes but not always.

I have checked the wiring to the relay and from the relay to the gate.

When checking the output from the LEM with a tester I noticed that normally the output produces about 4.6v current which jumps to just under 12v when the output is pulsed.  The next output (10) is producing about 3.2v normally and the remainder of the outputs on the LEM produce about 0.6v normally.

Is this normal?

Any assistance you could provide in assisting me to resolove this issue would be appreciated.

Regards,

Clinton.

 

[admin]

Outputs driving relays can get damaged by back EMF from the relays if there is no reverse diode across the coil of the relay. The Output driver IC has a built in reverse diode, but may also be damaged in certain circumstances.
Turn on the Output using action or the O!nnss command on the UCM (nn is the output number in hexadecimal, ss = 01 for ON) and do the measurement with stable voltage on the outputs. you should get under 1 V, otherwise the output is damaged
With Comfort I you can change the Output driver IC which is on a socket.

[cgiltrow]

Thank you for getting back to me.

I assume that when the output is on then the voltage must be 12v and when the output is off then the voltage must be less then 1v?  Is that correct?

How do I get a new driver IC if neccessary?

Regards,

Clinton.

[admin]

It depends on what you are measuring
The outputs are transistor outputs. When the output is on, the voltage goes low to 1V and when off, the output is 12V provided there is a load across the terminals.
If you are measuring the voltage between the common centre terminall of the terminal block (which is at 12V) and the output itself, then you would see 11V when the output is ON and 0V when the output is off, as this is the difference in voltages.

Note that if you have no load connected to the output and the output is off, you will not be able to measure any voltage as the output will be floating.

[admin]

You can order some output drivers (U6) to replace them. It is a good  idea to keep some in spare if you have Comfort I. Igshaan Collins may have some of these