RKI Instruments RM-5000 Series Indicator/Alarm Unit - Manual (Page 48)

6 Operations and Functions 6-3. External output operation
RM-5000 - 48 -
6-3. External output operation
Specifications 4 - 20 mA RS-485 (option)
Signal Transmission System Electric current transmission (non-isolated) Two-wire digital data transmission
system
Transmission Path CVVS KPEV-S
Transmission Distance Below 1 km (Depending on the system designing
conditions)
Connection Load Resistance Below 300 Ω -
(1) Detection Mode (No Alarm) 4 - 20 mA (concentration output) Concentration data
(2) Detection Mode (Gas Alarm) 4 - 20 mA (concentration output) Concentration data, Alarm bits
(3) Initial Clear Depending on the setting of (4)
2.5 mA setting: 2.5 mA
4 mA, HOLD, 4 - 20 mA setting: 4 mA*
Initial bit
(4) Maintenance mode 2.5 mA setting: 2.5 mA
4 mA setting: 4 mA*
HOLD setting: The previous value retained
4-20 mA setting: 4 - 20 mA (concentration output) Concentration data, Adjustment bit
(5) Alarm Test Output ON setting: 4 - 20 mA (concentration output)
Output OFF setting: Depending on the setting of (4) Concentration data, Adjustment bit, Test
bit
(6) Fault Alarm 0.5 mA (Fixed) Fault bits
(7) Inhibit Depending on the setting of (4)
2.5 mA setting: 2.5 mA
4 mA, HOLD, 4 - 20 mA setting: 4 mA*
Concentration data, Adjustment bit,
Inhibit bit
(8) Power Off 0 mA Signal OFF
* OX-5001,OX-5002: 0 - 25 vol% is equivalent of AIR (20.9 vol% = 17.4 mA)
Example of Gas Concentration and External Output (4 - 20 mA)
CAUTION
<<4 - 20 mA>>
• The 4 - 20 mA output is already adjusted. In case of over scale, an output will not exceed 22 mA.
• Output during inhibit or initial clear is based on 4 - 20 mA output setting in the maintenance mode.
2.5 mA
4 mA
20 mA
22 mA
Full scale
Gas concentration
External output
0
Zero suppression
Detection mode
Maintenance mode