I 2 C Bus; Lcd/Display Module; Relay Pca - Teledyne T200 Operation Manual

Troubleshooting & Service
2
12.7.3. I C BUS

12.7.4. LCD/DISPLAY MODULE

12.7.5. RELAY PCA

250
Teledyne API – T200 NO/NO2/NOx Analyzer Operation Manual
Table 12-7: DC Power Supply Acceptable Levels
VOLTAGE
POWER
SUPPLY
PS1 +5
PS1 +15
PS1 -15
PS1 AGND
PS1 Chassis
PS2 +12
PS2 DGND
2
Operation of the I C bus can be verified by observing the behavior of D1 on the relay
PCA & D2 on the Valve Driver PCA. Assuming that the DC power supplies are
operating properly, the I
the Valve Driver PCA are flashing
There is a problem with the I
Driver PCA are ON/OFF constantly.
TOUCHSCREEN INTERFACE
Assuming that there are no wiring problems and that the DC power supplies are
operating properly, the display screen should light and show the splash screen and other
indications of its state as the CPU goes through its initialization process.
The Relay PCA can be most easily checked by observing the condition of the status
LEDs on the Relay PCA (see Section 12.3.2), and using the SIGNAL I/O submenu
under the DIAG menu (see Section 12.1.3) to toggle each LED ON or OFF.
If D1 on the Relay PCA is flashing and the status indicator for the output in question
(Heater power, Valve Drive, etc.) toggles properly using the Signal I/O function, then
the associated control device on the Relay PCA is bad.
Several of the control devices are in sockets and can be easily replaced. The following
table lists the control device associated with a particular function:
Table 12-8: Relay PCA Control Devices
FUNCTION
All valves
Reaction Cell Heater
NO  NO Converter heater
2
Permeation Tube Heater for
Optional Internal Span Gas Generator
CHECK RELAY BOARD TEST POINTS
FROM
Test Point
NAME # NAME
DGND 1
AGND 3
AGND 3
AGND 3 DGND
DGND 1 Chassis
+12V Ret 6
+12V Ret 6 DGND
2
C bus is operating properly if D1 on the relay PCA and D2 of
2
C bus if both D1 on the relay PCA and D2 of the Valve
CONTROL DEVICE
MIN V
TO
Test Point
#
+5 2 +4.85
+15 4 +13.5
-15V 5 -13.5
1 -0.05
N/A -0.05
+12V 7 +11.8
1 -0.05
SOCKETED
U5 Yes
K1 Yes
K2 Yes
K4 Yes
06858E DCN7057
MAX V
+5.25
+16.0
-16.0
+0.05
+0.05
+12.5
+0.05