BMT 932 - Appendix R: Relay Box (Option)

OZONE MONITOR BMT 932 Manual, Rev. 02/2021
51
Appendix R: Relay Box (Option)
The optional Relay Box may be built into the OZONE MONITOR BMT 932 (19" rack mount
version only) allowing port identification signals and threshold alarm information for each sample
point to be put out via relay contacts. A 50-pole D-SUB connector on the rear panel is used to
interface the relays. It is only available for three and six channel instruments. One channel in-
struments offer all contacts on the signal connectors, already.
This optional Relay Box is identical to that found in the OZONE MONITOR BMT 930
(copy exact). Order number is 932-RELAY.
For each of the six sample points there are three relays available which put out the following in-
formation:
 Identification of the sample point providing a measurement result at the moment (closing
contacts)
 Low alarm threshold exceeded (closing and opening contacts)
 High alarm threshold exceeded (closing and opening contacts)
Voltages of up to 30 V (DC or AC) can be applied. Current per relay should not exceed 1 A.
Output data of the Relay Box will be updated with every completed measurement. If the instru-
ment is powered off, the Low and High Alarms will be active.
The following table describes the pinout of the D-SUB connector:
Sample Sample ID
(closing)
Low Alarm High Alarm
Common Opening Closing Common Opening Closing
1 1  34 5 38 22 11 44 28
2 2  18 6 39 23 12 45 29
3 19  35 7 40 24 13 46 30
4 3  36 8 41 25 14 47 31
5 4  20 9 42 26 15 48 32
6 21  37 10 43 27 16 49 33
Example for sample port 1, Low Alarm active: pins 5 and 38 are open, pins 5 and 22 are con-
nected.
When Power is applied and the instrument is in AUTO mode, the low and high limit alarms on
the Relay Box will remain active until an air sample having an ozone content below the set
threshold has been measured on the corresponding sample port. Threshold alarms of disabled
sample ports (see page 28 under "Set Active Channels") will become inactive immediately after
completion of warm-up.
If during operation of the OZONE MONITOR BMT 932 an instrument error occurs (e.g. Lamp
Low, Low Flow), all threshold alarm contacts of the Relay Box will move into the alarm position.