Teledyne T100, Instruction Manual, Page: 46 / 404

Getting Started
Teledyne ML - T100 UV Fluorescence SO2 Analyzer
46
3.4.4.1. CONVERTING CURRENT LOOP ANALOG OUTPUTS TO STANDARD VOLTAGE
OUTPUTS
To convert an output configured for current loop operation to the standard 0 to 5 VDC
output operation:
1. Turn off power to the analyzer.
2. If a recording device was connected to the output being modified, disconnect it.
3. Remove the top cover

Remove the set screw located in the top, center of the rear panel

Remove the screws fastening the top cover to the unit (four per side).

Lift the cover straight up.
4. Disconnect the current loop option PCA from the appropriate connector on the
motherboard (refer to Figure 3-8).
5. Each connector, J19 and J23, requires two shunts. Place one shunt on the
two left most pins and the second shunt on the two pins next to it (refer to
Figure 3-8).
6. Reattach the top case to the analyzer.
The analyzer is now ready to have a voltage-sensing, recording device attached to that
output.
Calibrate the analog output as described in Section 4.8.4
3.4.5. CONNECTING THE 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
(PLCs). Each status bit is an open collector output that can withstand up to 40 VDC.
All of the emitters of these transistors are tied together and available at the “D”
connector pin.
ATTENTION
COULD DAMAGE INSTRUMENT
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, an external
dropping resistor must be used to limit the current through the transistor output to less
than 50 mA. At 50 mA, the transistor will drop approximately 1.2V from its collector to
emitter.