Envoy Application Programming Manual

Table Of Contents
TINET Multipoint Supervisor Protocol
Envoy Application Programming Manual427159-001
8-14
Polling Type
The supervisor polls each station in the network a maximum of ten times for each call to
the READ procedure when the line is in the CONTROL state. If polling is currently in
progress, the change does not take effect until the next call to READ from the
CONTROL state.
Specific Polling
Specific polling causes a designated terminal to be polled once. The polling of only one
specified terminal is designated with a call to the CONTROL procedure. The
CONTROL operation is 13 (send EOT). You can enable a specific poll by setting
control parameter.0 to 1. Control parameter.8:15 specifies the entry number of the
terminal in the address list to be polled.
The specific poll actually takes place the next time the READ procedure is called.
Depending upon the terminal’s response to the poll, the READ can complete in one of
the following ways:
If the terminal responds to the poll with a message, the READ completes with an
error 0 (operation successful) indication.
If the terminal responds with an EOT sequence, the READ completes with an error
176 (poll sequence ended with no responder).
If the polled terminal fails to respond to the poll or if an incorrect response is
received, the READ completes with an error indication; the entry number of the
terminal in error is returned in the MCW.
Following a specific poll, subsequent polling reverts to the currently specified
polling type (that is, continuous or noncontinuous). Example 8-5 shows specific
polling using the sample address list presented in Address-List Format on page 8-7.
Terminal %041, the first entry in the address list, is polled one time. If the terminal
responds with a message, the READ completes with the message in linebuf and a CCE
indication; if the terminal responds with an EOT sequence, the READ completes with an
error 171 (no response or invalid response received).
Example 8-5. Specific Polling
CALL CONTROL (linefnum, 13, %100001);
IF < THEN ...
CALL READ (linefnum,linebuf,...);
IF < THEN ...