Chapter 9 Optional Equipment
The following table is for when the relays are set to normally open.
Status Pin Relay Closed Relay Open
Concentration Alarm 8 Alarm No Alarm
Local or Remote Mode 9 Local or Service Mode Remote Mode
MG/M
3
or PPM Mode 10 mg/m
3
mode ppm mode
General Alarm 11 Alarm No Alarm
Zero Gas Mode 21 Zero Mode On Zero Mode OFF
Span Gas Mode 22 Span Mode On Span Mode Off
Table 9-1.
Instrument Status Output Truth Table
4-20 mA ISOLATED CURRENT OUTPUT
A 4-20 mA Isolated Current Output enables the CO concentration to be output at 4-20
mA as shown in Table 9-2 and Figure 9-7.
Current Output
Channel
Output #1 Output #2 Output #3 Output #4
Range Mode
Single CO CO Unused Unused
Dual Low CO Hi CO Unused Unused
Auto CO Status High = 12
mA
Status Low = 4 mA
Unused Unused
Table 9-2
Current Output Channel with Corresponding Concentartion
Figure 9-7.
Pin-Out of Rear Panel Terminal Strip for Optional Current Output
9-9