B&B Electronics 232MSS2 - Manual - Manual (Page 14)

Documentation Number 232MSS2-0812Manual
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104
B&B Electronics Ltd – Westlink Commercial Park – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445
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Table 3 - Timer Values
The Set Timer Mode command requires the third byte to be an
ASCII “M”. If the data byte (fourth byte) is an ASCII “0”, zero
(default), the timer will be setup as an inactivity timer. For example,
sending the following string to the 232MSS2 will set up the timer as
an inactivity timer (assuming programmable character is the factory
default of 2).
SetTM$ = CHR$(27) + CHR$(2) +”M” + “0”
The “M” tells the 232MSS2 it is the set timer mode command and the
“0” indicates to set up up the timer as an inactivity timer.
When configured as an inactivity timer, the 232MSS2 will monitor the
data lines (TD & RD) for data. If there is no activity for the specified
timer value, the slave port that is connected to the master port will be
disconnected. In smart switch mode, the inactivity timer can be used
to prevent the preamble codes from being received by the slave
devices. In port combiner mode, the inactivity timer can be used to
prevent devices from tying up the master port. For example (port
combiner mode), all the slave ports have their handshake lines
asserted. The device on Port C has its handshake line asserted and
is currently connected to the master port, but has not been
transmitting or receiving data. When the inactivity timer expires, Port
C will be disconnected and the next slave port will then be connected
to the master port (following the first-come-first-serve rule). Port C
will then be placed at the “end of the line”.
If the data byte of the Set Timer Mode command is an ASCII “1”,
the timer will be setup to ignore switching commands. Sending the
following string to the 232MSS2 will set up the timer to ignore
switching commands. (Assuming programmable character is the
factory default of 2).
SetTM$ = CHR$(27) + CHR$(2) +”M” + “1”
Data Byte Value
0 timer disabled
1 10ms
2 25ms
3 100ms
4 500ms
5 1 s
6 5 s
7 30 s
8 1 min.
9 5 min.