[32]
PAGING SESSION LOGIN
The v9 Paging Session Login mode allows a host device, sometimes called a
REMOTE ENTRY DEVICE
,
to initiate communications with the paging system.
With the WaveWare v9E Paging Systems, the login
process is optional
, because, it will automatically login to a host device and process paging messages if it
recognizes a properly formatted TAP message block at any point in its operation. Below is a step by step
breakdown of the login process.
1.
The host device initiates the Login process by transmitting a carriage return
<CR>
character
a.
The system should respond with:
ID=<CR>
(
The ID=<CR> will not be repeated or timed out.
)
2.
The host device should respond with:
<ESC>PG1<CR> or <ESC>pg1<CR>
a.
The system should respond with:
110 1.8<CR>WaveWare Paging Encoder v9.00<CR><ACK><CR>
3.
The system then notifies the host device that it is ready to accept messages with:
<ESC>[p<CR>
PAGING OPERATION
Paging transactions are transmitted in blocks of characters, where one transaction is sent per block.
Each block sent by a host device is acknowledged by the paging system. The Host Device must wait for this
acknowledgement before sending the next block.
The WaveWare v9E Paging Systems provide
acknowledgement in the form of an <ACK> character.
SPS5 Paging Systems support TAP message blocks up to 253 characters in length, with a 235 to 244
character message, from 1 to 10 characters for ID, plus 5 control characters, and a 3 character checksum.
THE TAP MESSAGE LENGTH EQUATION IS AS FOLLOWS:
253
–
ID length
–
5 ctrl char.
–
3 checksum char.
THE TAP MESSAGE BLOCK FORMAT IS AS FOLLOWS:
<STX>ID<CR>Message<CR><ETX>Checksum<CR>
Leading zeroes are not required for the ID field; the message field may be empty except for the
carriage return in the data block; the checksum field provides a sum of the digits for the previous portion of
the TAP message block, which is checked before transmission to detect errors in the data.
See Appendix C –
TAP Checksum Calculation, for sample code to create the checksum field.
2
The “110 1.8” message indicates that the system conforms to TAP specification version 1.8 and should be
backward compatible with earlier TAP implementations.
