Teledyne 3000MA - Paramagnetic oxygen analyzer - Manual (Page 29)

Percent Oxygen Analyzer Installation 3
3-9 Teledyne Analytical Instruments
st Toggling input. Stops/Starts any status message output from
the RS-232, until st is sent again.
The RS-232 protocol allows some flexibility in its implementation.
Table 3-2 lists certain RS-232 values that are required by the 3000MA
implementation.
Table 3-2: Required RS-232 Options
Parameter Setting
Baud 2400
Byte 8 bits
Parity none
Stop Bits 1
Message Interval 2 seconds
3.3.3 Remote Probe Connector
The 3000MA is a single-chassis instrument, which has no Remote
Probe Unit. Instead, the Remote Probe connector is used as another method
for controlling external sample/zero/span gas valves. See Figure 3-6.
Figure 3-6: Remote Probe Connector Pinouts
Due to power supply limits, the maximum combined current that can be
pulled from these output lines is 100 mA. (If two lines are ON at the same
time, each must be limited to 50 mA, etc.) If more current and/or a different
voltage is required, use a relay, power amplifier, or other matching circuitry
to provide the actual driving current.
In addition, each individual line has a series FET with a nominal ON
resistance of 5 ohms (9 ohms worst case). This could limit the obtainable
voltage, depending on the load impedance applied. See Figure 3-7.