Minder general inputs

Hi guys, long time reader first time poster.

I have a clients decommmisioned minder that uses the general inputs to get 7 zones of floor temperature off a third party system for slab heating. I don't know what that system is, only that it connects to the inputs via figure 8 cables.

These inputs have been replaced with general input units. In the minder config the temperature was being stored to a group address as a level, e.g. 30 degrees would set the group level to 30. Then the logic code was if "floor temp 1" < 25 then turn on "floor temp 1 control" and so on.

The issue I'm having is that I can't work out how to get the general input units to read the data; it either records the level as 0 or something outrageous like 87 and doesn't move.

I've tried all of the value types (resistance, amps, voltage) in toolkit with no joy. In minder, there is value conditioning which appears to equate to scale and offset in toolkit, but none of the types will play ball with recording correct temperature data. The property manager says that floor heating was working when the minder was in service so I assume that it was recording temps correctly.

Has anyone out there come across a similar issue or can point me in the right direction? Cheers and beers.

 

First thing to do is figure out how the minder was reading them.

What terminals were they connected to on the minder?
Is there also a resistor on each input as well?
In the minders configuration, how are the inputs configured?

Cheers

Rohan

 

Thanks for the reply mate and sorry for the late response!

All the input cables were connected to Common and A, B of each channel was left empty. There is no resistor on any of the inputs. According to the connection diagrams on the general input unit config, this would indicate that it is a voltage input.

There is where I come a cropper - I can't work out how the input was read in the original minder config. I've attached a screenie of the minder config page - there is a value conditioning field which appears to equate to the scaling and offset options in toolkit's general input config but values don't really make sense. nor work when configured that way. As you can see the range is simply set to degrees. Other options are farenheit, digital, custom or protected loop.

 

I managed to find a minder installation manual and one of the pages lists the inputs types as a "5225 Temp Sensor". Rhamer it seems you've come across these before?

I also found this in a clipsal tech update:

"C-Bus 5504GI , General Input Unit and Homeminder Temp sensors 5225 ( 25-10-04 )
Please note the Homeminder temperature sensors 5225 are not directly compatible with the
5504GI unit. The 5225 was specifically designed for Homeminder controllers where the
controller provides 9.75 volt to the sensor then reads a value back from the sensor into
Homeminder.
The 5504GI General Input Unit does not source voltage to sensors or devices connected to it.
Due to the cease of CIS manufacturing Homeminder, we will in turn be dis-continuing any
products used solely for it, such as LCD keypads, Temp sensors, etc."

So my question now is is there a temp sensor that you guys use?

 

Yep these are a LM35 Temperature sensor that output 10mV/DegC.

The likely problem is the A Terminal on the minder has an internal pull up resistor that powers the LM35, and this is probably not there on the general input unit.

Off hand I don't know how to configure the general input unit to do what you need, but I would suspect you will need to add the pull up resistor (or possibly just enable it) and then you will read the input as a voltage that corresponds to temperature.

if I get a minute I'll lookup the General input specs to see how it can be done.

Cheers

Rohan

 

Seems I was typing as you were.

Rohan

 

Thanks for the info Rohan. Although I'm an electrician I don't have much experience in electronics - do you know how I might go about implementing a pullup resistor and what size to use?

 

When I initially replied, I was hoping there was just an option in the GIU to enable a pull up. However after reading your follow up post with Clipsal's statement about the Minder sensors not being directly supported I think it could get quite complicated.

The short story is the LM35 is really a 3 wire device (+, output, -) and the original Minder (or should I say Jeeves) folks implemented a bit of trickery to make it work in a different mode and only require 2 wires. Some of this circuitry is in the sensor housing, and some is in the Minder. So it would take a bit of mucking around to make it work, and possibly even a separate power supply for them.

To put it more simply, if this was my house then I would fiddle around and probably get it to work, but for a commercial job it wouldn't be worth the time and effort and may not ever be satisfactory.

If you can get to the sensors then I would replace them with devices that are directly compatible with the GIU. That way you are working with known quantities and guaranteed results, instead of hours of trial and error.

Also I'm assuming you are aware there is now a C-Bus 4 channel dedicated temperature measuring unit available. I'm pretty sure it uses DS1820 sensors that run down 2 wires. Perhaps that would be an even simpler solution.

Cheers

Rohan

 

Thanks for your help on this matter Rohan. I've investigated the 5225 temp sensors and it seems I can do a straight swap with the 5031RDTSL C-Bus temp sensors, just need to pull some new cable through.

Thanks again,

Joel.

 

It seems we posted at the same time again

 

SNAP

The 5031RDTSL devices are of course complete C-Bus units and not just sensors as you have now. simple solution, but a little pricey for 7 of them.

But as I encouraged, they are a guaranteed solution.

BTW how are they bonded in that housing to measure floor temperature?

Cheers

Rohan

 

Help me please

In one of the projects I have much groups of light and other controlled objects and control devices, so I had to create two networks, both networks include all controlled objects, but control devices are devided between this two networks. So I have a problem, one of the movement sensors is placed in one network and the relay module in second one, so there is a problem with switching the light, that is controoling by this movemet sensor threw relay. What could be done to improve the situation without transfer thesensor from one network to another. Can be the problem in the bridge?

 

You might get a better response if you post this question in a new thread.

The thread you have posted in is about an old obscure product that doesn't interest many people.

 

I'm going out to site in the near future to do a proper audit so will let you know. Thanks again for your assistance.