14 • MRLDS-450 Refrigerant Gas Detection I&O Manual
026-1316 Rev 0
4.1.2. Verifying Analog Signals
The MRLDS-450 gas detector features a single configurable analog output. During
normal operation, the analog output of the instrument is proportional to the detected
gas concentration and can be selected from the following:
• 1 to 5V (Default)
• 0 to 5V
• 2 to 10V
• 0 to 10V
• 4 to 20mA
The MRLDS-450 Gas Detector uses different voltage/current values to indicate
various modes of operation. In normal operation the relative gas concentration
output is indicated by the analog output level. Output level is proportional to the gas
level as shown in
:
Table 4-2
- Gas Concentration Levels
Gas Concentration
1-5V
0-5V
2-10V
0-10V
4-20mA
0%
1V
0V
2V
0V
4mA
50%
3V
2.5V
6V
5V
12mA
100%
5V
5V
10V
10V
20mA
The instrument may also enter several special states, these are indicated by the
specific analog output levels indicated in
Table 4-3
- Analog Output Levels
Mode of Operation
1-5V
0-5V
2-10V
0-10V
4-20mA
Instrument Fault
≤ 0.3V
N/A
≤ 0.6V
N/A
≤ 1.2mA
Offline Mode/Maintenance
0.75V
N/A
1.5V
N/A
3mA
Drift below zero
0.95V
N/A
1.9V
N/A
3.8mA
Normal operation
1-5V
0-5V
2-10V
0-10V
4-20mA
Measuring range exceeded
5.12V
5.12V
10.25V
10.25V
20.5mA
Fault on analog interface
> 5.25V
> 5.25V
> 10.5V
> 10.5V
> 21mA
4.1.3. Verifying the Modbus Signal
The MRLDS-450 Gas Detector provides a Modbus RTU digital interface. All status
messages and most parameters that can be accessed and/or configured through the
Bluetooth® interface can also be accessed and/or configured via RS485 for Modbus
RTU.