Harvey
Newbie
Posts: 7
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« on: March 16, 2010, 09:23:33 am » |
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New to direct soft. I need to drive the input high if there a thermocouple is disconnected or shorted. any ideas
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Gene Bond
Newbie
Posts: 4
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« Reply #1 on: March 16, 2010, 08:30:19 pm » |
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Forgive me, but I've not used this card, but couldn't you do do a couple of compares that are out of your normal range for alarms? Seemsif the T/C is shorted, the register would read very low, surely lower than normal for the process, and if it's open, it should read very high...
Again, maybe not applicable, but it may help.
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b_carlton
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« Reply #2 on: March 16, 2010, 10:10:31 pm » |
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The manual defines that there are "Broken Transmitter Bits".
As far as 'shorted', Gene's suggestion to test against any possible normal measurement is a good one. Be aware though that a shorted thermocouple - the two leads shorted together at some place other than the normal measuring end - will measure the ambient temperature at the shorted point.
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An output is a PLC's way of getting its inputs to change.
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Harvey
Newbie
Posts: 7
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« Reply #3 on: March 17, 2010, 07:56:35 am » |
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Open it is reading low, if I unwire the t/c it will read 92 deg what I would like this be a read high so the heater does not keep trying to heat. Other plc cards I have used have a way to configure this; I have not worked much with direct soft.
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b_carlton
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« Reply #4 on: March 17, 2010, 08:49:37 am » |
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I repeat: The manual defines that there are "Broken Transmitter Bits". It's not a function of Directsoft. It's a function of the thermocouple card. Read the instructions carefuilly. |
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An output is a PLC's way of getting its inputs to change.
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Harvey
Newbie
Posts: 7
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« Reply #5 on: July 31, 2010, 01:43:57 pm » |
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yes it is "Broken Transmitter Bits"in on the f4-08thm not the -n. On the f4-08thm-j card it is to go high same as burned out thermocouple this is staying at 95 deg when the termocouple is unplugged.
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Controls Guy
Internal Dev
Posts: 1134
Darth Ladder
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« Reply #6 on: July 31, 2010, 01:53:05 pm » |
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There is no F4-08THM-N listed as a part number on the website.
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I retract my earlier statement that half of all politicians are crooks. Half of all politicians are NOT crooks. There.
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b_carlton
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« Reply #7 on: July 31, 2010, 02:37:16 pm » |
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The 'F4-08THM-N' is a shorthand for either of the older cards F4-08THM-J or F4-08THM-K which were single single type thermocouple specific. The (I believe) newer F4-08THM accepts a variety of thermocouples.
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An output is a PLC's way of getting its inputs to change.
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Controls Guy
Internal Dev
Posts: 1134
Darth Ladder
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« Reply #8 on: July 31, 2010, 04:11:24 pm » |
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Oh, sorry, I assumed it was a module specific to Type N thermocouples analogous to the J and K-type cards.
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I retract my earlier statement that half of all politicians are crooks. Half of all politicians are NOT crooks. There.
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Harvey
Newbie
Posts: 7
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« Reply #9 on: August 02, 2010, 09:22:36 am » |
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My understanding is with the F4-08THM card you can set up each channel for a different type of thermocouple with a jumper, thank you for all the help and input.  |
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