Fluke 943-227-15 User Manual

2-4 

The following Test are provided on the 977-200-15M board: 
 
Table 2-4.  977-200-15M Test Points 

TP1 Electrometer 

Output 

TP2 

Analog +5 VDC supply 

TP3 

- 5 VDC supply 

TP4 

Digital +5 VDC supply (From 977-210-10M) 

TP5 

High Voltage Sense (Not Used) 

TP6 

+ 12 VDC supply (From 977-210-10M) 

TP7 DC 

Ground 

TP8 

Programmable Gain Amplifier Output 

TP9 

Microprocessor Clock Signal 

TP10 

Chip Enable - EPROM 

2.4  977-210-10M Interface Board 

Refer to the Communications Interface, P/N 977-210-13M, schematic diagram in Appendix B.  U12 is an 
asynchronous communications interface adapter (ACIA) which communicates with the UDR or 960 
system.  U1 is an analog switch used to select either the 

Victoreen loop or the RS232 driver/receiver for 

external communications.  Optical isolation U10 isolates data transmitted on the 

Victoreen loop while the 

circuitry comprised of Q6, Q7, Q14, and Q18 are the actual loop drivers.  Optical isolator U8 isolates the 
receive data from the Victoreen loop. 
 
U2 and U3 are, respectively, the receiver and driver circuits for the RS232 port.  U14 decodes address 
block A000 to provide chip enables to the ACIA switch input register U6. 
 
Regulated power for the electronics (+/- 12 VDC) is derived from three terminal regulators VR3 and VR4.  
The ±5 Vdc logic power is derived from the three terminal regulators VR1 and VR2.   
 
 
Power for the detector is normally provided by the electronic high voltage power supply in the associated 
Model 942A-200C UDR or Model 960 System. 
 
The following LEDs are provided to indicate operation of certain functions of the 977-210-10M board: 
 
Table 2-5.  977-210-10M LEDs 

LED1 

+15 VDC is being supplied to the circuit board 
from the UDR when ON 

LED2 

Communications – Receive;  
ON (bright): both + 15 and -15 volt loops 
present 
ON (dim): Only one loop supply present 
OFF: no loop voltage from either supply 

 
The following Test are provided on the 977-210-10M board: 
 
Table 2-6.  977-210-10M Test points 

TP2 RS232 

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