Rockwell Automation 1746-BLM Blow Molding Module Installation Instructions - Manual (Page 37)

Blow-molding Module 37
Publication 1746-IN014B-EN-P - January 2001
Step: 11 Calibrating the module
To achieve precise closed-loop position control, you must calibrate the module’s
analog inputs. The module uses calibration data to transform setpoints/process
variables to/from 16-bit signed integer format to the corresponding voltages present
at the analog inputs.
You may calibrate the module in either of two ways:
•
open loop
•
closed loop
Closed Loop Calibration
You may calibrate the module’s analog output by moving the mandrel (ram) to its
limits of travel. To do this in closed loop mode, first download an axis control
structure to the module with -32768 and +32767 for the zero- and full-scale
calibration data, respectively. This insures that the module is able to move the
mandrel (ram) over its full range of travel.
Then proceed with the open-loop procedure.
Open Loop Calibration (or continuation of closed-loop procedure) :
1. Move mandrel (ram) to its fully-open position.
2. Set the full-scale calibration control bit in the output file. The module
acknowledges by setting the full-scale status bit in the input file.
3. Move mandrel (ram) to the fully-closed position.
4. Set the zero-scale calibration control bit in the output file.
The module again acknowledges by setting the corresponding bit in the
input file. At this point the full- and zero-scale calibration data may be read
from M1 file in shared memory after issuing an upload- axis-status-structure
command via the output file.
5. Copy the new calibration data to the M0 file in shared memory.
Issue the download-axis-control-structure command.
The new calibration data will take effect.