Instruction manual

Troubleshooting and Repair
128 025-9416
Audible Tones Frequencies Cadence Indicated Activity
di di di di dit 1000 Hz di - 50 msec
off - 50 msec
Page has been accepted
busy 480 + 620 Hz on - 500 msec
off - 500 msec
Invalid subscriber ID, page rejected, or
other error
fast busy 480 + 620 Hz on - 250 msec
off - 250 msec
End of telco call
TROUBLESHOOTING TNPP PAGING
Most problems that occur with TNPP paging involve a network link that is down. In effect, the
paging terminal cannot connect to the receiving link and send pages. A down link may be the
result of modem communication errors, a faulty RF link, transmitter deviation, or any other prob-
lems with the network link equipment. In addition, the test light on the TNPP interface card may
flash to indicate the link is down.
Many times the TNPP problem occurs on a per-page basis. That is, some TNPP pages are
correctly received and/or sent, but others fail. These types of errors are indicated by descriptive
response messages in the log files. Sometimes the destination node is invalid or undefined.
Usually if the Model 640 is unable to pass pages on to another paging terminal (TNPP node), the
logs show a “page no dest” response.
Note: Zetron recommends enlisting the assistance of a Mobile and Paging Systems Division
applications engineer to troubleshoot TNPP problems. This subsection is only
provided as a general overview of the errors that can occur with a TNPP-equipped
paging terminal.
TNPP Interface LEDs
The TNPP interface card has six red LEDs that identify operation of the card. Although these
LEDs are not visible if the top panel of the Model 640 chassis is installed, it is important to
describe them for troubleshooting purposes. If a malfunction of the TNPP interface is suspected,
remove the top panel of the paging terminal and observe the operation of the LEDs at the middle
rear of the chassis. Figure 63 shows a side view of the TNPP interface board (Part No. 702-
9362).