Switch User Manual

10 Documentation Number 232BSS4-2907m
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax [phone] – www.bb-elec.com
B&B Electronics – Westlink Commercial Park – Oranmore, Galway, Ireland – Ph [phone] – Fax [phone] – www.bb-europe.com
A summary of the control characters for each combination of ports
is given in Table 2.2.
For instance, to broadcast to ports B & C, send:
{Char1}{Char2}{Char3}”S”{Decimal 6}
(B = 2, C = 4, 2 + 4 = 6)
VB Example:
BroadcastBC$ = CHR$(27) & CHR$(2) & “S” & CHR$(6)
Clear Receive Buffer
– “X” + one control byte specifying which ports’
buffers to clear.
The Clear Buffer command will tell the 232BSS4 which Slave
ports’ receive buffers to purge. If the Master device is only interested in
the most recent data from the Slaves, this command can be used to
delete old data from one or more of the Slave port buffers before it is
sent to the Master.
The lowest four bits of the control byte tell the 232BSS4 which
ports’ buffers to purge. Bit 0 represents port A, Bit 1 represents port B,
Bit 2 represents port C, and Bit 3 represents port D. In decimal, this is
represents a value of 1, 2, 4, and 8 respectively. To clear more than one
buffer with a single command, the decimal equivalents of each port
would be added together to give the final byte.
A summary of the control characters for each combination of ports
is given in Table 2.2.
For instance, to clear the receive buffer on ports A & D, send:
{Char1}{Char2}{Char3}”S”{Decimal 9}
(A = 1, D = 8, 1 + 8 = 9)
VB Example:
ClearAD$ = CHR$(27) & CHR$(2) & “X” & CHR$(9)