Carel GDWB, User Manual

16

ENG

+0300046IE - rel. 1.2 - 14.01.2021

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Enable 120Ω termination: used to enable the 120 Ω termination. This 
termination must be activated if the device is located at the end of the 
RS485 Modbus network bus, so as to reduce signal reflections along 
the serial line that can cause communication problems.

Default value: disabled.

WARNING

: given the presence of the “Enable 120Ω termination” 

function, the GLD series gas detectors do not require physical installation 
of a terminating resistor.

OUTPUTS

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Analog Output Range: this is used to set the required type of analogue 
output. 
Options: 4-20 mA, 0-5 V, 1-5 V, 0-10 V or 2-10 V.
Default output: 4-20 mA.

• 

Buzzer: used to enable or disable the buzzer. 
Default value: enabled. 

NOTICE

: when disabled, the buzzer will not sound for alarms or 

faults, however will sound on establishing a Bluetooth connection.

• 

Relay Failsafe: this function is used to reverse operation of the relays, 
meaning they will be energised during normal operation. This 
therefore guarantees that the relays will be activated in the event of a 
power failure that switches the device off. For details on this function, 
see paragraph “5.5 - Relay logic table”.
Default value: disabled.

• 

Alarm Delay: this function is used to set a delay time (in minutes) that 
the device will wait before activating an alarm. If the condition that 
caused the alarm is no longer present (even briefly), the timer is reset 
and will start counting down again from the set value. This function 
can be used to prevent short transients of high gas concentrations 
from triggering alarms. 
Possible values: from 0 to 15 minutes. 
Default value: 0 minutes.

• 

Analog Zero Adjust: use the slider to adjust the analogue output by 
applying a fixed offset. This is essential for voltage analogue outputs, to 
compensate for the voltage drop due to cable resistance.
Possible values: from -10% to + 10% with reference to the full-scale 
value. 
Default value: 0%.

• 

Analog Span Range: use the slider to adjust the analogue output 
range to a percentage of the concentration range (in ppm) that can 
be measured by the gas detector. For example, for a gas detector set to 
measure R-1234yf, 0-1000 ppm, with a 4-20 mA analogue output, if the 
analogue span range is set to 20%, the entire analogue output range 
covers just the first 20% of the gas measurement range. Therefore, 
the output will be 4-20 mA in therefore in the range 0-200 ppm. For 
concentrations between 200 and 1000 ppm, the analogue output will 
remain at 20 mA.
Possible values: from 20% to 100%. 
Default value: 100%.

3.7.7 Logs tab

The Logs Tab shows the list of previous calibrations and bump tests and 
the corresponding reports generated. The list can be cleared by pressing 
the “Clear” button. The calibration logs can also be viewed from the “View 
logs” sub-menu, accessible from the pop-up menu at the top left.

3.7.8 Unlock code

For security reasons, access to the configuration, test and calibration 
options is restricted to authorised users only. Access to these features 
requires an unlock code. 
The default unlock code for the device is “1234”.
The device will remain unlocked until the Bluetooth® connection is 
terminated.

IMPORTANT

: do not confuse the “password” (default “123456”) 

required for the Bluetooth® connection with the “unlock code” (default 
“1234”) required to access the device configuration.

WARNING

: the default alias, password and unlock codes can be 

changed from the Configure tab. The default values need to be changed 
after installing the device for security reasons.

Fig. 3.k