Western Telematic PollCat III, Руководство по обслуживанию

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5. Refer to Figure 2.3 and find the UART at board location
U22. Use an oscilloscope to check the UART. While
transmitting data to the PollCat III, the pins should behave
as follows:
a)
Pin 31: (Receive Data Signal for PBX Port A) ~+5 VDC
b) Pin 10: (Receive Data Signal for PBX Port B) ~+5 VDC
c) Pins 16 through 19 and 21 through 25: The Data
Receive Signal is then sent out on the data bus lines.
The UART at board location U22 is not a socketed IC and
should only be replaced by a qualified technician. Please
contact WTI Technical Support as described in Appendix F
for further information.
Note:
·
Failure of the PBX LED driver can also inhibit the
data signal from IC U27 or U28 to the UART at
board location U22.
·
The PBX LED driver is found at board location U2.
The driver for the PBX A LED receives signals from
IC U27 at pin 11. The driver for the PBX B LED
receives signals from IC U28 at pin 11.
9-6
PollCat III Service Guide