Rs232C Line Control Signals - IDEC FC4A-C10R2 User Manual

RS232C Line Control Signals

While the
MicroSmart
DTR control signal options for port 2. Port 2 is available on the 16- and 24-I/O type CPU modules only, and an optional
RS232C adapter must be installed on the port 2 connector to enable the RS232C communication. The DSR and DTR con-
trol signal options cannot be used for port 1.
The RTS signal line of port 2 remains on.
Special Data Registers for Port 2 RS232C Line Control Signals
Special data registers D8104 through D8106 are allocated for RS232C line control signals.
RS232C Port
Port 2
Control Signal Status D8104
Special data register D8104 stores a value to show that DSR and DTR are on or off at port 2. The data of D8104 is updated
at every END processing.
D8104 Value
0
1
2
3
DSR Control Signal Status in RUN and STOP Modes
Communication
Mode
User
Communication
Mode
Maintenance Mode
DTR Control Signal Status in RUN and STOP Modes
Communication
Mode
User
Communication
Mode
Maintenance Mode
is in the user communication mode, special data registers can be used to enable or disable DSR and
DR No. Data Register Function
D8104 Control signal status
D8105 DSR input control signal option
D8106 DTR output control signal option
DTR
OFF
OFF
ON
ON
D8105 Value
0 (default)
1
2
3
4
5 or more
—
D8106 Value
0 (default)
1
2
3 or more
—
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17: U
Every scan
When sending/receiving data
When sending/receiving data
DSR
OFF Both DSR and DTR are off
ON DSR is on
OFF DTR is on
ON Both DSR and DTR are on
RUN Mode
No effect
ON: Enable TXD/RXD
OFF: Disable TXD/RXD
ON: Disable TXD/RXD
OFF: Enable TXD/RXD
ON: Enable TXD
OFF: Disable TXD
ON: Disable TXD
OFF: Enable TXD
No effect
No effect
DTR (Output) Status
RUN Mode
ON
OFF
RXD enabled: ON
RXD disabled: OFF
ON
ON
S U ' M
ICRO MART SER S ANUAL
C
SER OMMUNICATION
DR Value Updated
Description
DSR (Input) Status
STOP Mode
No effect (TXD/RXD disabled)
No effect (TXD/RXD disabled)
No effect (TXD/RXD disabled)
No effect (TXD/RXD disabled)
No effect (TXD/RXD disabled)
No effect (TXD/RXD disabled)
No effect
STOP Mode
OFF
OFF
OFF
OFF
ON
»
I
NSTRUCTIONS
R/W
R
R/W
R/W
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