
Model 400E Ozone Analyzer
Instruction Manual
Getting Started
P/N 04316 Rev: B
27
The pin assignments for the Status Outputs are:
Rear Panel
Label
Status
Definition
Condition
1
SYSTEM OK
On if no faults are present.
2
CONC VALID
On if O3 concentration measurement is valid.
If the O3 concentration measurement is invalid, this bit is OFF.
3
HIGH RANGE
On if unit is in high range of DUAL or AUTO Range Modes.
4
ZERO CAL
On whenever the instrument is in CALZ mode.
5
SPAN CAL
On whenever the instrument is in CALS mode.
6
DIAG MODE
On whenever the instrument is in DIAGNOSTIC mode.
7
SPARE
8
SPARE
D
EMMITTER BUSS
The emitters of the transistors on pins 1-8 are bussed together.
SPARE
+
DC POWER
+5 VDC
Digital Ground
The ground level from the analyzer’s internal DC Power
Supplies.
NOTE
Most PLC’s have internal provisions for limiting the current that
the input will draw from an external device. When connecting to
a unit that does not have this feature, a 120 ohm external
dropping resistors must be used to limit the current through the
transistor output to 50mA or less. Refer to the Mainboard
schematic 04070 in Appendix F.
4.
If you wish to use an external device to remotely activate the Zero and Span
calibration modes, several digital Control Inputs are provided via an 8-pin
connector labeled CONTROL IN on the analyzer’s rear panel.
There are two methods for energizing the Control Inputs. The in5V
available from the pin labeled “+” is the most convenient method however, to
ensure that these inputs are truly isolated a separate, external 5 VDC power
supply should be used.