TC-MIDI (+)
4.4 Signal outputs
The device provides different status signals. The maximum
switching load of the alarm outputs is limited to
250 V AC/150 V DC, 2 A, 50 VA each.
An alarm is triggered by the alarm contact/status output (S2)
if the temperature of the cooler is outside the specified limits.
It does not indicate if the alarm was triggered due to excess
temperature or insufficient temperature.
The front film has three LEDs:
Colour
Marking
Function
Red
S2
High/low temperature, device error
Yellow
S1
---
Green
OP
Normal operation
The LEDs OP and S2 indicate the device status similar to S2.
If the option “temperature signal” is built in, the unit has a
signal output via the analogue output to indicate the actual
cooler temperature.
When the moisture detector (optional) is installed, an alarm is
activated by the alarm contact/status output (S2) if the mois-
ture is still present in the prepared sample gas. Thereby, no
distinction is made between the alarm/cable break triggered
by moisture detector 1 or 2. This information is displayed by
an error message instead.
The temperature signal can be read via the panel plug (S3) us-
ing the M12x1 connector. This plug is located next to the mois-
ture detector connectors at the top of the cooler.
Description of signal outputs
Function/
contact type
Description
Re-
gar
d-
ing
S2)
internal
changeover
contact:
max.
250 VAC/150
VDC, 2 A,
50 VA
the following
device
statuses can
be indicated
via two
switching
outputs:
Contact between 3 and 2
closed (alarm)
• No mains voltage and/or
actual temperature out-
side the alarm
thresholds
Contact between 3 and 1
closed (OK)
• Mains voltage attached
+ actual temperature
within the alarm
thresholds
With moisture detector op-
tion
Contact between 3 and 2
closed (alarm)
• The moisture detector
registers residual hu-
midity in the sample gas
or cable break: Error
message
Contact between 1 and 3
closed (OK)
• no residual moisture in
measuring gas/no cable
break
With temperature signal op-
tion
Re-
gar
d-
ing
S3)
4-20 mA
analogue
output
(R
Load
<500 Ω
)
Signalling of
actual tem-
perature
T
cooler
= -20 °C
≙
(-4 °F) ->
4 mA/ 2 V
T
cooler
= 5 °C
≙
(41 °F) -> 9 mA/
4.5 V
T
cooler
= 60 °C
≙
(140 °F) ->
20 mA/ 10 V
Re-
gar
d-
ing
S4)
Digital out-
put
Modbus RTU
(RS-485)
Interface default values
Baudrate – parity – stop bit:
19200 – Even – 1
Default ID: 10
The bus lines are not intern-
ally terminated.
5 Operation and control
NOTICE
The device must not be operated beyond its specifications.
After switching on the cooler the block temperature will be
displayed. The display will flash until the block temperature
has reached the preset target value (± adjustable alarm
range). The status contact is in the Alarm position.
Once the target temperature range has been reached, the
temperature will continuously be displayed and the status
contact switches over.
14
Bühler Technologies GmbH
BX440016 ◦ 09/2021
