Siemens Compressed Air Meter - Into ComX200

[mcolston]

I have a Siemens Sitrans Flow meter FX300 which has a pulse output - but its open collector.

I've currently fitted a 3.3kOhm pull up resistor from the 12V to the input of the comx and to the +ve connection on the meter and the 0V of the comx to the -Ve on the meter. If I short the meter end I "see" the pulse.

However, the meter is not being picked up.

I've read the data sheet from Siemens and it seems to suggest a minimum of 14V is needed for the transistor to switch.

Can I use an external supply or do I have to put a semi-conductor relay in to isolate the meter pulse from the ComX

[Anonymous user]

Hi Mark,

I've forwarded your question along to one of our engineers to get you a response. I'll let you know!

Best,

Colton

[mcolston]

Hi Colton, We have managed to sort this by using a 24v DC PSU to allow the meter to drive it correctly.

Seems to be working.

Mark.

[Anonymous user]

Great! Glad to hear its resolved.