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Temperature, Humdity,
Pressure Transmitters
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#1 17-09-2019 16:07:02
- benbridges
- Member
- Registered: 17-09-2019
- Posts: 3
More than 5 channels on P8541
I have a P8541 with 4 temperature & humidity sensors connected. Currently, channels 1,3,4 & 5 are displaying temperature and channel 2 the humidity of sensor 1. This means I cant read the temperature and humidity from all sensors at once. Is it possible to have more virtual channels so I can read all the info from all sensors at the same time?
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#2 18-09-2019 07:12:47
- HonzaD
- Administrator
- Registered: 11-08-2008
- Posts: 294
Re: More than 5 channels on P8541
Hi,
Unfortunately you will not be able read all values (temperature and humidity) from all your probes at one P8541 device. P8541 have four connectors but it is supported up to 5 "virtual channels". For getting all values from your 4 probes, you will need to use two P8541 devices. P8541 device does not have capability increase number of internal channels.
P8541 devices are commonly used with combinations like a:
- Four temperature probes
- One temperature+humidity probe and three temperature probes
- Etc.
As to be honest, we haven't had a requirement to measure out of four T+RH probes at one P8541 device. I am just a curious what is your application for such use case?
Regards,
Jan
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#3 18-09-2019 10:32:22
- benbridges
- Member
- Registered: 17-09-2019
- Posts: 3
Re: More than 5 channels on P8541
We are using them in a large heated shed used for curing large amounts of concrete. As such the humidity can vary a lot and can easily vary across the room.
If I can't have more virtual channels, is there a way I can programmatically change the settings on the P8541 so I can switch between which physical sensor is being read by one of the virtual channels. Then I can just pull the info from each sensor and store the results externally.
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#4 18-09-2019 11:54:58
- HonzaD
- Administrator
- Registered: 11-08-2008
- Posts: 294
Re: More than 5 channels on P8541
Hi,
I am sorry, but this way is not possible. For changing sensors (measured value) at channel is mandatory save configuration into internal flash memory of P8541 device. Often changing values in flash memory will damage this memory soon. From this reasons we not recommend this type of use.
I think there are two options:
- use additional P8xxx device
- use different type of device which supports up to four probes. For example M1140 device. Unfortunately price will be much higher that using P8541 device.
Jan
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#5 18-09-2019 12:03:31
- benbridges
- Member
- Registered: 17-09-2019
- Posts: 3
Re: More than 5 channels on P8541
No problem, thanks for your help
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