Function Channels - Ahlborn ALMEMO 2590-2 Operating Instructions Manual

12.10 Function channels

At the end of the table of measuring ranges and units (see above) under the
sub-heading function channels there is a group of ranges that can be used to
represent function parameters for measured value processing or for calculated
results obtained by linking certain measured values on measuring channels
(see Manual 6.3.4). Reference to the actual measuring channels is provided by
one or two reference channels. For all function channels there are preferred
channels on the appropriate connector; reference channel programming is not
required because these values are referred to by standard reference channels
Mb1 and Mb2.
Function
* Humidity variables, capacitive
* Humidity variables, psychrometric on channel 3 or 4
Function parameter (Mb1)
Difference (Mb1 - Mb2)
Average value over Mb2...Mb1
Total value of Mb2...Mb1
/
M01−M00 
q
WBGT
Arrangement of channels on the connectors
2590-2
sensor channels
4. chan. 30
20
3. chan.
10
2. chan.
1. chan. 00
M0 M1 M2
Once the range has been programmed the standard reference channels can
be used (see above). Settings for the reference channels are described in Sec-
tion 12.12.6.
A new feature is the presence of 4 device-internal channels. The first
(M2/M3/M4) is programmed by default as differential channel M1 – M0 (see
10.3), if two sensors with the same units and same decimal point position are
connected at measuring points M0 and M1; the fourth is used for average val-
ues (see 11.2). However, all four channels can be used in conjunction with any
function channels with standard reference channels Mb1 = M1 and Mb2 = M0; i.e.
if you want to program a function parameter without reference channel on a de-
vice-internal basis, the sensor must be connected to M1.
Function channel
on channel 3 or 4
on channel 2, 3, or 4
on channel 2, 3, 4 (Mb1)
on channel 2, 3, 4 (Mb1)
on channel 2, 3, 4 (Mb1)
on channel 2, 3, 4 (q)
on channel 2 (GT)
2590-3
sensor channels
Device
internal
channels
30 31
31 32
20 21
21 22
10 11
11 12
00 01
01 02
M0 M1 M2 M3
Reference chan-
nel 1
Mb1 = temperature
Mb1 = TT
Mb1 = channel 1
Mb1 = channel 1
Mb1 = channel 1
Mb1 = channel 1
Mb1 = channel 1
Mb1 = channel 1 Mb2=M00
2590-4
sensor channels
Device
internal
channels
32 33
30
22 23
20
12 13
10
02 03
00
M0 M1 M2 M3 M4
ALMEMO
Function channels
Reference
channel 2
Mb2 = humidity
Mb2 = HT
Mb2=M00
Mb2=M00
Mb2=M00
Mb2=M05
Device
internal
channels
Average
31 32 33 34
21 22 23 24
11 12 13 14
Difference
01 02 03 04
M01-M00
® 2590 53