105BCommunication processor
12.4 Universal serial interface (USS) communication
S7-1200 Programmable controller
System Manual, 11/2011, A5E02486680-05
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Table 12- 36 Data types for the parameters
Parameter and type
Data type
Description
RUN
IN
Bool
Drive start bit: When true, this input enables the drive to run at the
preset speed. When RUN goes to false while a drive is running, the
motor will be ramped down to a stop. This behavior differs from the
dropping power (OFF2) or braking the motor (OFF3).
OFF2
IN
Bool
Electrical stop bit: When false, this bit cause the drive to coast to a stop
with no braking.
OFF3
IN
Bool
Fast stop bit: When false, this bit causes a fast stop by braking the
drive rather than just allowing the drive to coast to a stop.
F_ACK
IN
Bool
Fault acknowledge bit: This bit is set to reset the fault bit on a drive.
The bit is set after the fault is cleared to indicate to the drive it no longer
needs to indicate the previous fault.
DIR
IN
Bool
Drive direction control: This bit is set to indicate that the direction is
forward (for positive SPEED_SP).
DRIVE
IN
USInt
Drive address: This input is the address of the USS drive. The valid
range is drive 1 to drive 16.
PZD_LEN
IN
USInt
Word length: This is the number of words of PZD data. The valid values
are 2, 4, 6, or 8 words. The default value is 2.
SPEED_SP
IN
Real
Speed set point: This is the speed of the drive as a percentage of
configured frequency. A positive value specifies forward direction
(when DIR is true). Valid range is 200.00 to -200.00.
CTRL3
IN
Word
Control word 3: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)
CTRL4
IN
Word
Control word 4: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)
CTRL5
IN
Word
Control word 5: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)
CTRL6
IN
Word
Control word 6: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)
CTRL7
IN
Word
Control word 7: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)
CTRL8
IN
Word
Control word 8: A value written to a user-configurable parameter on the
drive. You must configure this on the drive. (optional parameter)
NDR
OUT
Bool
New data ready: When true, the bit indicates that the outputs contain
data from a new communication request.
ERROR
OUT
Bool
Error occurred: When true, this indicates that an error has occurred and
the STATUS output is valid. All other outputs are set to zero on an
error. Communication errors are only reported on the USS_PORT
instruction ERROR and STATUS outputs.
STATUS
OUT
Word
The status value of the request indicates the result of the scan. This is
not a status word returned from the drive.
RUN_EN
OUT
Bool
Run enabled: This bit indicates whether the drive is running.
D_DIR
OUT
Bool
Drive direction: This bit indicates whether the drive is running forward.
INHIBIT
OUT
Bool
Drive inhibited: This bit indicates the state of the inhibit bit on the drive.
FAULT
OUT
Bool
Drive fault: This bit indicates that the drive has registered a fault. You
must fix the problem and then set the F_ACK bit to clear this bit when
set.