Not Enough Outputs

Hi everyone,

I ran into a problem today when wiring my PLC (Mitsubishi Melsec FX-32MR) which has 17 inputs and 17 relay type outputs.

I have 3 Solenoid Valves and 3 Bilge Pumps (all 12v), and I have 9 indication lamps (24V)
My problem is if i allocate COM 1 and COM 2 to 12V Outputs and COM 3 and COM 4 to 24V outputs. I only have 8 24V outputs and I need 9.

I could get a 12V lamp but they're quite expensive or else they wont arrive by the time ive to demo this project, could I do anything else with this?

Thank you

Also,sorry if this question is stupid I've just hit a wall with this problem

Why not use an external relay 24v coil? This would be an intermediate relay.

Regards,

I think that would be a 12 volt intermediate relay for the 9th lamp.

note that you don't have 17In 17 out, you have 16 in 16 out..
0..17 in octal = 0..15 in decimal

Wire them all 24V and use 24V relays for your 12V stuff.

You don't mention the spec of your valves and pumps, but use that to work out what size relay you need.

6 of these, for example.
https://uk.rs-online.com/web/p/non-latching-relays/1357375/

If you're tight up for cash, you can buy just two of these, and wire the other 4 outputs through your PLC via COM1 or whatever.

For future, 24V is more standard in industrial applications if you can avoid 12V products.

Another option is to have one of your LEDs never come on

Thank you

Thanks guys. I wish I knew 24V components would of made my life easier but I guess I've learned a valuable lesson from this

I will be able to get 24V relays from the college thankfully.

An LED indicator rated at 24Vdc will still light at 12V, just not as bright. This is how I fixed the backlight in the clock in my car.