Control Techniques UD78, Руководство пользователя, Страница: 20 / 38

UD78 User Guide
Issue code: 78nu2
16
Output and Input modes
RX TERM
TX
TERM
RX\
RX
TX\
TX
0VSC
PL1 [UD78]
0VSC
RX\
TERM
TX\
TERM
PL1 [UD78]
RX TERM
TX
TERM
RX\
RX
TX\
TX
0VSC
0VSC
RX\
TERM
TX\
TERM
Parameter 11.24 set at
OUtPUt (2) Parameter 11.24 set at
InPUt (3)
Figure 8 Serial communications connections for the Input and
Output modes
Data is transferred at a rate of at least 140Hz. The protocol and range of
baud rates allow communications with the Mentor II and CDE models, as
well as other Unidrive models.
Only the value of a variable parameter can be transmitted and received. Bit
parameters are excluded.
Set parameter
11.24
Serial comms. mode selector as follows:
Output mode:
OutPUt
(2)
Input mode:
InPUt
(3)
Output mode
The value of a variable parameter selected by parameter 11.27
Serial comms.
source selector is sent (after scaling by
11.28
Serial comms. parameter
scaling ) to the serial communications port for transmission.
If the Drive trips, the value
0
is transmitted.
Input mode
The value received by the serial communications port is applied (after
scaling by
11.28
Serial comms. parameter scaling ) to an unprotected variable
parameter selected by parameter
11.27
Serial comms. destination selector.
If communications fail, the Drive will trip; the display will indicate
SCL
.
Ground connection
In addition to each end of the cable shield being connected to 0V, it can be
connected by a single path to a ‘clean’ ground.