TM 11-6625-3145-14
Maintenance: Troubleshooting-318/338 Service
17. SERIAL TEST
Program: TSTSR1 (power on), TSTSR2 (Troubleshooting)
Setup: - Loop-back test data of TSTSR2 is supplied from the RS-232 port, so the P6107 SERIAL INPUT PROBE must be
connected to pin #2 of the RS-232 connector.
Function:
Power on - TSTSR1 initializes the SIO Port-A and reads the initial status. If the initial status is good, it loads dummy data
into the SIO and checks for any status change.
Troubleshooting - The TSTSR2 diagnostic program has the following three functions:
1.
checks the SIO Port-A status
2.
checks external trigger circuit
3.
checks data passing through the circuit
Function 1 includes six test programs. These programs read the initial status of the SIO Port-A.
Function 2 includes two test programs. These programs control the external trigger transition and check the trigger status
in bit #1 of the 318S1/338S1 status register.
Function 3 includes eight test programs. These programs generate serial data (shift pattern data: 01 02 04 08 10 20 40) at
pin #2 of the RS-232 connector. The programs also check incoming data at SIO Port-A. Serial data speed is changed
automatically during the test.
(The test data format is fixed at eight bits/word, even parity, and one stop bit. The data threshold is TTL, and data polarity
is NEGATIVE.)
Description- Refer to the 318S1/338S1 1/0 function list and the simplified diagram of the Serial Acquisition and RS-232
circuits when reading following.
SIO Port-A is used for serial data acquisition. The Port-A address is 90 and 91, and the SERIAL parameter selector
address is 8C.
U31 latches the baud select data, input data polarity bit, and the external trigger polarity bit. These are the parameters for
serial acquisition control.
U6 generates the receive data sampling clock and supplies this clock to SIO pin #13. U22 switches the input clock
selector from either the 19.2 K internal clock or the external clock, but the TSTSR2 program does not test this logic.
The external trigger polarity is defined by U12, and U22 latches on the transition of U12’s output. This status is initialized
by writing data to address 84. External trigger status appears at bit 0 of the 318S1/338S1 status register; its address is 80.
The serial input data level is divided by 10 at input and this signal is amplified 2.5 times by U100 before reaching test point
10. The data at test point 10 is compared with Threshold C (supplied from the RAM board through bus connector 39B) by
U110; then data polarity is defined by U12 and supplied to SIO pin #12.
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Summary of Contents for 318
Page 119: ...318 VERIFICATION AND ADJUSTMENT PROCEDURES ...
Page 182: ...338 VERIFICATION AND ADJUSTMENT PROCEDURES ...
Page 253: ...318 ___________________ TROUBLESHOOTING TREES ...
Page 344: ...338 TROUBLESHOOTING TREES ...
Page 517: ...TM 11 6625 3145 14 318 338 4434 923 318 Block Diagram ...
Page 518: ...TM 11 6625 3145 14 318 338 4434 924 338 Block Diagram ...
Page 519: ...TM 11 6625 3145 14 318 338 4434 925 318 Acquisition Module Wiring Diagram ...
Page 520: ...TM 11 6625 3145 14 318 338 4434 926 318 338 Mainframe Wiring Diagram ...
Page 521: ...TM 11 6625 3145 14 318 338 4434 926 338 Acquisition Module Wiring Diagram ...
Page 522: ...TM 11 6625 3145 14 318 338 4434 928 Figure 9 1 318 A01 Input A Board Component Locations ...
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Page 528: ...TM 11 6625 3145 14 Figure 9 3 318 338 A03 ACQ Control Board Component Locations ...
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Page 542: ...TM 11 6625 3145 14 Figure 9 8 318 338 A10 CRT Board Component Locations ...
Page 544: ...TM 11 6625 3145 14 Figure 9 9 318 338 A11 Inverter Board component Locations ...
Page 546: ...TM 11 6625 3145 14 Figure 9 10 318 338 A12 Regulator Board Component Locations ...
Page 551: ...TM 11 6625 3145 14 Figure 9 12 338 A01 Input A Board Component Locations ...
Page 553: ...TM 11 6625 3145 14 318 338 SERVICE ...
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Page 555: ...PIN 058584 ...