4.4.2 Analog Inputs
The instrument is also equipped with three analog inputs with resolution of 15 bits plus polarity,
accepting a voltage between 0 - 5 V. These go directly to the microprocessor and should be protected
to ensure static/high voltage does damage the main controller PCA (instrument warranty does not
cover damage from external inputs).
4.4.3 Digital Status Inputs
The instrument is equipped with eight logic level inputs for the external control of the instrument such
as Zero or Span sequences. Each input has a terminating resistor which can be either PULL UP or PULL
DOWN. This is set using the jumper JP1 on the rear panel PCA (refer to Figure 85).
4.4.4 Digital Status Outputs
The instrument is equipped with eight open collector outputs which will convey instrument status
condition warning alarms such as no flow, sample mode, etc. Two of the digital outputs can be set so
that there is +5 V and +12 V available on the 25 pin connector for control purposes, instead of digital
outputs 0 and 1.
In the default jumper locations (refer to Figure 85) these two outputs will function normally as open
collector outputs. If moved to the position closer to the 25 pin connector, then the DO 0 will supply
+12 V and DO 1 will supply +5 V.
The +12 V and +5 V supplies are limited to about 100 mA each.
Each digital output is limited to a maximum of 400 mA. The total combined currents should not exceed
2 A.
Figure 85 – 25 Pin Rear Panel PCA (Default Jumpers Highlighted)
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