Principles of Operation Teledyne API T703/T703U Calibrator Operation Manual
200

9.2.4.5. External Digital I/O

The external digital I/O performs two functions.
The STATUS outputs carry logic-level (5V) signals through an optically isolated 8-pin
connector on the rear panel of the calibrator. These outputs convey on/off information
about certain calibrator conditions such as CONC VALID. They can be used to
interface with certain types of programmable devices.
The CONTROL outputs can be used to initiate actions by external peripheral devices in
conjunction with individual steps of a calibration sequence (see Section 6.5.1.6).
The CONTROL inputs can be initiated by applying 5V DC power from an external
source such as a PLC or data logger (Section 6.5.1.5). Zero and span calibrations can be
initiated by contact closures on the rear panel.

9.2.4.6. I2C Data Bus

I2C is a two-way, clocked, bi-directional, digital serial I/O bus that is used widely in
commercial and consumer electronic systems. A transceiver on the motherboard
converts data and control signals from the PC-104 bus to I2C. The data is then fed to the
relay board, optional analog input board and valve driver board circuitry.

9.2.4.7. Power-up Circuit

This circuit monitors the +5V power supply during calibrator start-up and sets the
analog outputs, external digital I/O ports, and I2C circuitry to specific values until the
CPU boots and the instrument software can establish control.

9.2.5. POWER SUPPLY AND CIRCUIT BREAKER

The calibrator operates in two main AC power ranges: 100-120 VAC and 220-240 VAC
(both ± 10%) between 47 and 63 Hz. A 5 ampere circuit breaker is built into the
ON/OFF switch. In case of a wiring fault or incorrect supply power, the circuit breaker
will automatically turn off the calibrator.
NOTE:
The calibrator is equipped with a universal power supply that allows it to accept any AC power
configuration, within the limits specified in Table 2-2.
CAUTION
Should the power circuit breaker trip, correct the condition causing this situation
before turning the calibrator back on.
07223C DCN6572