10: U
SER
C
OMMUNICATION
I
NSTRUCTIONS
10-36
FC5A M
ICRO
S
MART
U
SER
’
S
M
ANUAL
FC9Y-B1268
DSR Input Control Signal Option D8105 (Port 2 to Port 6) and D8205 (Port 7)
Special data registers D8105 and D8205 are used to control data flow between the MicroSmart RS232C port 2 through
port 7 and the remote terminal depending on the DSR (data set ready) signal sent from the remote terminal. The DSR sig-
nal is an input to the MicroSmart to determine the status of the remote terminal. The remote terminal informs the
MicroSmart using DSR whether the remote terminal is ready for receiving data or is sending valid data.
The DSR control signal option can be used only for the user communication through the RS232C port 2 to port 7.
The control status of each port is allocated as shown below:
Bit 15
0
2
0
1
0
0
D8105
0
3
Port 2
0
6
0
5
0
4
0
7
0
8
Port 3
Port 4
0
9
0
12
0
11
0
10
0
13
0
14
Port 5
Port 6
Bit 15
0
2
0
1
0
0
D8205
Port 7
D8105/D8205
3-bit Binary Value
Description
000
DSR is not used for data flow control. When DSR control is not needed, set 0 to D8105/D8205.
001
When DSR is on, the MicroSmart can transmit and receive data.
DSR signal
ON
OFF
Possible
Impossible
Impossible
Transmit/receive
010
When DSR is off, the MicroSmart can transmit and receive data.
DSR signal
ON
OFF
Possible
Impossible
Impossible
Transmit/receive
011
When DSR is on, the MicroSmart can transmit data. This function is usually called “Busy Control” and is used
for controlling transmission to a remote terminal with a slow processing speed, such as a printer. When the
remote terminal is busy, data input to the remote terminal is restricted.
DSR signal
ON
OFF
Possible
Impossible
Impossible
Transmit
100
When DSR is off, the MicroSmart can transmit data.
DSR signal
ON
OFF
Possible
Impossible
Impossible
Transmit
101
Same as D8105/D8205 = 000. DSR is not used for data flow control.
Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: [email protected]