area compare Omron C200H

Hi everyone,

we measure the temperatur on a castiron valve for vulcanisation with a thermocouple. this one stays in place with a magnet. now the temperatur is monitored and if the time and the SV temperature is reach our press will open. Sometimes it happens that the thermocouple fals off. Then the cure time is to long. Now i want to know when the thermocouple fals off.
Í wanted to use the ZCP function but i can only set a givin area. Because the temperatur will rise during the cure time i want to make a bandwith of +10 degrees, -10 degrees of the actual temprature. can this be done with the ZCP function and if so, how?

Thanx in advance.

what is the temperature range you are using?

next, what does the zcp function do?

i failed to find in in the manual, must have overlooked it.

regards,
james

The temperature range is from 18 to 130 degrees. the temperature will slowly increase. As shown with attached images. I can only set a range like min and max given over the total slope time. Hope the images i made in paint are some what understandable.

After banging my head several times against a wall, i got an flash of inspiration. I'm not at work at this moment, but can anyone confirm if the attached picture could work?

I assume you have the set point value and are reading the thermocouple in the PLC. You could look at using ZCP or BAND for this (have not done this before).
Take the set point value and place in a DM. Use the DM as the value in the instruction so that if it changes it will be reflected in the value in the instruction.
ADD 10 to the setpoint value for the upper limit into another DM, similarly subtract 10 into another DM for the lower limit and point to these DMs in the instruction for the upper and lower limits.
Which PLC you have will determine what you can use - looks to me like it is an old PLC. Please confirm PLC type and I will look again.

you could buy a high temperature prox switch and make a fixture placing the face on the part. if the part falls off, the plc will alert you via a signal beacon.

regards,
james

Thanx everyone for replying,

I assume you have the set point value and are reading the thermocouple in the PLC. You could look at using ZCP or BAND for this (have not done this before).

Click to expand...

Thanx i will look in to this. think ZCP wont work and i''ll take a look in the band function.

Which PLC you have will determine what you can use - looks to me like it is an old PLC. Please confirm PLC type and I will look again.

Click to expand...

Its a C200HE cpu 42 and yes they are very old.

you could buy a high temperature prox switch and make a fixture placing the face on the part. if the part falls off, the plc will alert you via a signal beacon.

Click to expand...

We are testing some idea's to get this. but there are several presses so it will take some time to make this. In the meanwhile we're trying this sollution.