Data Output - Siemens SINUMERIK 840 Planning Manual

06.91
3.3.3.3.2

Data output

DTR
DSR
CTS
RTS
RxD
TxD
DTR is activated after initialization of the interface.
The pin assignments refer to the transmitter shown in the figure of Section 3.3.3.2.
After initializing the interface, the DTR signal line is activated. After a transmitting job has been
transferred to the transmitting scratch (output buffer of the respective procedure), the
procedure driver is started. Depending on the configuration, the DSR status is checked before
transmitting the first character. A waiting period for the first XON character can also be
configured.
Data transmission is interrupted only after XOFF is transmitted by the receiver. The procedure
driver waits for the XON control character to be transmitted until the monitoring time T
has.elapsed.
If the monitoring time T expires without an XON character received, the transmitting job is
m
returned to the transmitter with a negative acknowledgement.
The monitoring time T is necessary for enabling the interface after a failure of the peripheral
m
unit.
The following parameters of the XON/XOFF procedure are configurable:
Transmission rate
Monitoring times
DSR evaluation
Number of end identifiers
Node states equal
Waiting for the 1st XON
XON character
XOFF character
Line reservation time
© Siemens AG 1989 All Rights Reserved
SINUMERIK 840/880 (PJ)
T
m
XOFF
Data
Transmitting job Receiving
buffer full
(Speed of data transmission)
(Character delay or character monitoring times and device
monitoring time)
(Check if node is active)
(Number)
(Yes/no)
(Transmitting station waits for the receiver to transmit the first
XON before starting transmission)
(Hexadecimal value)
(Hexadecimal value)
(Monitoring time after initialization conflict)
6FC5 197-0AB20-0BP0
3 Interface Modules
3.3.3 XON/XOFF procedure
XON XOFF
Data
Receiving buffer
ready to receive
m
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