1.12
1.6.2.7 Power Supply Unit 01100968
The power supply unit generates +5V d.c., 0V and +/-8V d.c. supplies and also two isolated
a.c. supplies for the analogue output and optional digital output board. An on/off signal is
generated to provide the microprocessor with an indication of the state of the power supply
unit.
In the case of electricity supply failure ('Brown Out') the operation of the microprocessor will be
closed down in a logical way. The power supply unit also receives a heater control signal which
actuates a solid state relay via an opto-coupler. This relay switches power through to the
heaters in the transducer unit.
1.6.3 Interface Unit
The Interface unit is used when the separation of the Transducer from the Control unit has to
be greater than 100m (330 ft). The link from the Interface unit to the Control unit is digital and
can be up to 500m (1600 ft).
The Interface unit is similar to a Control unit but has no keyboard or display. It includes a digital
output board (01100927). The Control unit used as the receiver comprises only a digital output
board (used as termination for the digital link from the Interface unit), microprocessor board
and display/keyboard.
The Control unit checks the status of the digital link and if corrupted information is received it
will alarm. The alarm is self cancelling once communication is re-established.
The Interface unit stores all the information in the system and when first powered-up, or after a
communications failure, this data has to be transmitted to the control unit. This takes
approximately 30 secs. During this time the display on the Control unit shows a flashing
sequence of hyphens and blanks.
The optional alarm relay card (01100936) can be mounted in either the Interface or Control
unit.
The optional auto-calibration relay card should be fitted in the Interface unit.
For servicing in a SAFE AREA ONLY, it is possible to connect a keyboard and display to the
microprocessor board in the Interface unit. This local keyboard takes precedence over control
signals from the Control unit.
1.7 OPTIONS
1.7.1 Alarm Board 01100936
The optional alarm board has four sets of change-over relay contacts. The analyser has 15
dedicated alarm functions, and any alarm function can be allocated to any relay, more than
one function can be allocated to the same relay and the same function can be allocated to
more than one relay.
To Next Page
Loading...
Need help?
General
