Table of Contents
Advertisement
Operating Instructions
6.8. External Digital I/O
6.8.1. Status Outputs
The Status Outputs report analyzer conditions via optically isolated NPN transistors
which sink up to 50 mA of DC current. These outputs can be used interface with
devices that accept logic-level digital inputs, such as Programmable Logic
Controllers (PLC's). Each Status bit is an open collector output.
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
The status outputs are accessed via a 12 pin connector on the analyzer's rear panel
labeled STATUS. The function of each pin is defined in Table 6-11.
112
Schematic 04070 in Appendix D.
1
2
3
4
Figure 6-4: Status Output Connector
NOTE
STATUS
5
6
7
8
Model 400E Ozone Analyzer
Instruction Manual
+
D
P/N 04316 Rev: B
Advertisement
Table of Contents
