Siemens SIMATIC S7-200 System Manual page 314

S7-200 Programmable Controller System Manual
Table 9-26 Motion Commands
Command
Commands 0 to 24:
Executes the motion specified in
profile blocks 0 to 24
Command 118
Activates the DIS output
Command 119
Deactivates the DIS output
Command 120
Pulses the CLR output
Command 121
Reloads the Current Position
300
Description
When this command is executed, the Position module performs the motion
operation specified in the MODE field of the profile block indicated by the
Command_code portion of the command.
In Mode 0 (absolute position), the motion profile block defines from one to four
S
steps with each step containing both the position (POS) and speed (SPEED)
that describes the move segment. The POS specification represents an
absolute location, which is based on the location designated as reference point.
The direction of movement is determined by the relationship between the
current position and the position of the first step in the profile. In a multi-step
move a reversal of direction of travel is prohibited and results in an error
condition being reported.
In Mode 1 (relative position), the motion profile block defines from one to four
S
steps with each step containing both the position (POS) and the speed
(SPEED) that describes the move segment. The sign of the position value
(POS) determines the direction of the movement. In a multi-step move, a
reversal of direction of travel is prohibited and results in the reporting of an error
condition.
In Modes 2 and 3 (single-speed, continuous operation modes), the position
S
(POS) specification is ignored and the module accelerates to the speed
specified in the SPEED field of the first step. Mode 2 is used for positive
rotation, and Mode 3 is used for negative rotation. Movement stops when the
command byte transitions to Idle.
In Modes 6 and 7 (single-speed, continuous operation modes with triggered
S
stop), the module accelerates to the speed specified in the SPEED field of the
first step. If and when the RPS input becomes active, movement stops after
completing the distance specified in the POS field of the first step. (The
distance specified in the POS field must include the deceleration distance.) If
the POS field is zero when the RPS input becomes active, the Position module
decelerates to a stop. Mode 6 is used for positive rotation, and Mode 7 is used
for negative rotation.
In Modes 8 and 9, the binary value of the RPS input selects one of two speed
S
values as specified by the first two steps in the profile block.
- - If the RPS is inactive: Step 0 controls the speed of the drive.
- - If the RPS is active: Step 1 controls the speed of the drive.
Mode 8 is used for positive rotation, and Mode 9 is used for negative rotation.
The SPEED value controls the speed of movement. The POS values are
ignored in this mode.
When this command is executed, the Position module activates the DIS output.
When this command is executed, the Position module deactivates the DIS output.
When this command is executed, the Position module generates a 50-millisecond
pulse on the CLR output.
When this command is executed, the Position module sets the current position to
the value found in the TARGET_POS field of the interactive block.