Temp 3 displaying inaccurately

[bbrally]

I have finally hooked up my BCS to the brewery to try and test a new user interface I am writing.

During this test I noticed that the Temp3 was reading higher than all the other temps. I applied boiling water to the probe and it did register a rise in heat, but it only went from 65 to 85 degrees.

I disconnected all temp probes from the BCS and Temp3 still registers 65 deg. while all others register off scale.

I've been using POST to write to the BCS for my interface and in the beginning, while I was learning, there were many "improper" posts. So I did a hard reset thinking I may have altered something. I still get the same results.

Here's a screen shot after the hard reset and with all probes disconnected:

BCS screen shot.png (88.85 KiB) Viewed 6436 times

This is the contents of ultemp:

ultemp = 0,0,0,0,0,0,659,0,0,0,0,0,0,0,0,0,0,0,0,-1,-1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

All temps read 0 but temp3 reads 659.

I'm only using 7 temps and could easily rewire and rewrite my interface to swap temp3 with temp7, but is there something else that may solve this?

[JonW]

Under "System Settings", what do your thermistor coefficients look like? Maybe you overwrote that area as well.

[bbrally]

I was just about to add that.

All the thermistor coefficients are the same and proper.

[JonW]

You say that all the other temp probes register "off the scale", but in reality, they are showing 0. A temperature of 0 usually is indicated when a sensor is not attached. Did the sensors previously register proper temperatures or is this the first time they have been attached and tested? If it is a new behavior, have you disconnected them and rewired since this started happening? Are you sure the wiring is proper? Have you power cycled since attaching the probes? (they are usually inaccurate when hot-plugged). Are the probes from ECC or elsewhere?

[bbrally]

All temps are registering 0 as none are connected. Temp3 should also register 0, but doesn't.

I disconnected all probes and then hard reset the BCS. I then removed power and after a minute applied power again. Display is as in first post.

I power down again and reconnected the probes, powering up and the problem remains (all temps displaying properly except temp3). Swapping probes has proven they are working properly.

The probes are from Derrin at Brewers hardware, but as this happens with none connected, I think the probes are not involved in this issue.

I don't remember if this was a problem in the past. I didn't pay close enough attention to the temp values as I was always focused on output control.

[ECC]

Completely disconnect all 4 of the green connection plugs on your BCS-462 and then read the resistance values in the Thermo Test page. They should read near 98.9k for disconnected probes. If its reading something else it could be a hardware problem. It would also be good to see the reading when the probes are connected.

[bbrally]

Here's the resistance values with the connectors unplugged:

BCS probe resistance connectors unplugged.png (9.83 KiB) Viewed 6409 times

And the values with the connectors plugged back in and the temp probes plugged in. (Temp7 not connected)

BCS probe resistance connectors plugged in.png (32.43 KiB) Viewed 6409 times

[JonW]

Are the temperatures that are showing in your second screen shot what is now showing on the thermometer dials on the home page? According to the data grid, most of the temps are 51/52 degrees. Is that what your current ambient temp is?

[bbrally]

Those temps are correct. The garage is still a little cold soaked from winter. That and mother nature hasn't let us leave winter yet this year. It's normally well above 70 during the day this time of year. But this year we have yet to even see high 60's.

[ECC]

The strange resistance readings with everything disconnected pretty much rules out a config or wiring problem. I'll send you a PM.