Created Date: August 27,2002

Created by: Juergen

I try to messure a temperature with the F2-04THM. I insert the following to my existing program (Dl250 CPU)

SP0 LD K8400

Out V7661 (slot2)

LDA O2000

Out V7671

How can I see the temperature on the disply?

Juergen

Created Date: August 28,2002

Created by: tweedy

The code you posted only sets up your module for using the POINTER method. For SLOT 2, the addresses used are V7662(# of channels) and V7672(Data Storage) (not V7661 as you note)

Here's the play by play of the POINTER CODE:

SP0 Runs only on Program to Run mode

transition

LD 8400 8 means use Binary (I use 0 for BCD)

4 means 4 channels

00 NOT USED for INPUT MODULES

OUT V7662 is special location to store # of

channels to scan.

LDA O2000 Loads the Octal value (address)

that will store the first channel

of data.

ie V2000 is Channel 1

V2001 is channel 2 etc,

Out V7672 Stores the above address as the

start location.

All you need to do then is to read your data at V2000 - V2003 after masking it . See page 10-15 of the DL205 analog modules manual.

Created Date: August 30,2002

Created by: Juergen

I have still a problem with it.

Do I have to connect the Thermocouple with 24V or other power supply? I thought that the power comes from the CPU.

Could somebody right me a complete example how to get the temperature from the thermocouple to the display (P420)?

Thanks a lot

Juergen

Created Date: August 30,2002

Created by: Tom Jenkins

Juergen, think about how a thermocouple (T/C) works. The two dissimilar metals inherrently create a voltage when there is a temperture difference between the connection and the other "end " of the circuit. This is the Seebeck effect. What any T/C device does is amplify the mV signal from the T/C and convert it to a more useable form. You never apply power to the T/C itself.

How do you know there is a 20° offset? Have you used the correct thermocouple wire? (you can't just slap some copper conductor on a T/C and have it work - precautions must be taken.) Have you used shielded cable? How are the T/C and the wire shielded and grounded? Are there any sources of EMI or RFI close? (T/C's are very sensitive to both!)

T/C's aer widely applied, and unfortunately widely mis-applied as well. Omega engineering has a very thorough and concise explanation of T/C's in their handbook/catalog. You might want to review it or something similar and check out your circuit.

Created Date: September 03,2002

Created by: Juergen

I use the themocouple wire PR-T-24, so that should not be the problem.

I can measure with the voltmeter that the wire sends different voltages, if the temperature is changing. These voltage changes I still can't see on the program!

Can anybody post a complete example program, please?

thanks,

Juergen

Created Date: September 05,2002

Created by: Tom Jenkins

Juergen, have you configured the OP-420 to read the register in your PLC? I don't want to be dismissive, but it sounds to me like you haven't really gone through the documentation on the Optimate and its configuration software to get an understanding of how it works. As with most operator interface devices you have to set it up with "links " to the PLC registers of interest, and describe the format of the data you want to display. You may also have to do some math in the PLC to get the temperature into a register as engineering units in a format (such as BCD/Hex) that is compatible with the Optimate.