Fluke Biomedical 956A-201-M2 - Manual (Page 30)

3-4
When a Fail condition occurs, other than power failure, the red FAIL alarm indicator illuminates and the
Fail relay coil de-energizes. On the 956A-201-M2, auxiliary relay K1 is hard wired to operate in parallel
with the Fail relay, to drive a local indicator. Internally, 120 Vac is hard wired from alarm output connector
P1 to the Fail relay contacts on P2-12, and 13. Refer to Modification Sheet 956A-201-M2MS and Loop
Drawing S174014C-102.
To return the channel to normal operation after a FAIL alarm, the condition that caused the alarm must be
located and corrected. Upon correction of the failure condition, the FAIL alarm will automatically close.
Check Source
The check source pushbutton and electronics are provided to verify detector operation. To operate the
check source, press the CHECK SOURCE pushbutton and hold it down. The Check Source LED will
illuminate, and the radiation value will increase. Releasing the check source pushbutton will allow normal
UDR operation. An internal configuration jumper (JP3-5) allows alarms to be activated or deactivated in
the check source mode. The analog outputs are forced to their low scale value during a check source
operation.
Trip Test, 956A-201-M2
A Trip Test Function has been added to the operating firmware of the 956A-201-M2. The purpose of the
function is to verify operation of the output relay, status indicators, display, and analog outputs.
Refer to the Operational Mode section for a complete description of Operation.
Firmware Version
This system requires a PROM for UDR operation. For the part number and the latest revision of the
PROM, see the Factory Test Data Sheet. Operation as described in this manual pertains to the PROM
defined in Section 1.1.
3.4 OPERATIONAL MODES
Normal Operation, Mode
The UDR is in normal operation when the UDR function switch is in any position except 8, and the Check
Source button is OFF. During normal operation, the display shows the dose rate data received from the
preamplifier in mR/h, R/h, or kR/h. The bargraph will also show the dose rate. The color of the illuminated
segments is green when the dose rate is below the WARN setpoint, amber when the dose rate is above
the WARN setpoint and below the HIGH setpoint, and red when the dose rate is above the HIGH setpoint.
The analog outputs are active and all alarms are enabled.
Data Entry Mode
Data Entry Mode is selected by pressing the ENTER pushbutton while the rotary FUNCTION switch is in a
valid setpoint position (see Setpoint Description). The selected setpoint is displayed in exponential
format (e.g. 1.00E2) with the left most digit flashing. Setpoints are entered in exponential format (e.g.
X.XXEN), where X is the mantissa and N is the exponent. The X value may be any integer value between
0 and 9. A positive exponent is entered by selecting the "E" symbol, and a negative exponent is entered
by selecting the "-" symbol. The N value may be any integer value between 0 and 9. If the FUNCTION
switch is not in a setpoint position, pressing the ENTER button has no effect. Refer to Table 3-3 for
FUNCTION switch positions.
In the Data Entry Mode, the bargraph and analog outputs remain active.