Software Features

SPC and MTConnect®

SPC: Saving Process Parameters

Statistical process control (SPC) is a software/hardware feature that saves selected program parameters in real time as a part program is executing. Desired parameters, which may include time and date, position, commanded and/or actual laser power, pulse conditions, etc., are automatically written to a designated hard disk file (see Figure 1).

The G80 command enables SPC and signifies what data should be saved. To save data in a file of your choosing, program G80 “FNAME”, where FNAME is any desired part and file name accessible from Windows (if no directory is specified, the file is written to C:\Cnc-Share\Output). The system first goes to the end of that file (if it exists), then writes a blank line, the time and date, and the SPC data. If no file name is specified, data is written to file Cnc-Share\Output\Process.

Note that although the $ parameters shown below can be used, the newer system parameters that begin with ‘?’ are preferred.

The data in Table 1 can be selectively saved by programming G80 followed by text containing appropriate $ commands. Text in a G80 block without $ commands is also transferred to the output file. G58 messages can also include $ commands to display data in the S94P message window.

Typical options for various SPC configurations

Figure 1 – Typical options for various SPC configurations

 

Table 1 – Statistical Process Control (SPC) Data

$T Time
$D Date
$B0 Breakthrough Detection logging off
$B1 Breakthrough Detection logging on
$E0 Do not log system errors
$E1 Log system errors with time and date
$E2 Log system errors without time and date
$F Commanded federate (inch/minute or mm/minute)
$Vn System variable value (n=variable number)
$P0 Laser commanded power (watts)
$P1 Actual power at laser
$P2 Actual power at workstation (requires optional power meter)
$Q0 Override summary
$Q1 Feedrate override (%)
$Q2 Power Override (%)
$M M-function report; lists those functions that are on:
M200-M211
M300-M330
$M9 System model number (430, 795, etc.)
$L5 Laser block number executed
$L9 Laser type number

The functions of the following $ commands are dependent on the laser type (CO2, fiber, or Nd:YAG) (see Table 2 and Table 3):

Table 2 – CO2 and Fiber Laser Commands

Command Function
LAS_NAME Laser name
LAS_TYPE Laser type number
LAS_DB-REC Database record
LAS_SHUTTER_OPEN 1 if shutter is open
LAS_PULSE_MODE 1 if laser is in pulse mode
LAS_AVE_POWER Average power
LAS_PULSE_FREQ Pulse frequency
LAS_PULSE_WIDTH Pulse width

Table 3 – Nd:YAG Laser Commands

Command Function
LAS_NAME Laser name
LAS_TYPE Laser type number
AS_SHOT_COUNT L Shot count
LAS_DB_REC Database record
LAS_ACTIVE_PULSE Active pulse tool
LAS_ACTIVE_WAVE Active wave tool
LAS_SHUTTER_OPEN 1 is shutter is open
LAS_PULSE_MODE 1 if laser is in pulse mode
LAS_DCRAIL1_VOLTS DC Rail 1 voltage
LAS_DCRAIL2_VOLTS DC Rail 2 voltage
LAS_LAMP1_CURRENT Lamp 1 current
LAS_LAMP2_CURRENT Lamp 2 current
LAS_LAMP1_VOLTS Lamp 1 voltage
LAS_LAMP2_VOLTS Lamp 2 voltage
LAS_HIGH_VOLTAGE 1 if high voltage on
LAS_LAMP1_POWER Lamp 1 power
LAS_LAMP2_POWER Lamp 2 power
LAS_DCLINK1_VOLTS DC Link 1 voltage
LAS_DCLINK2_VOLTS DC Link 2 voltage
LAS_AVE_POWER Average power
LAS_POWER_DENSITY Power density
LAS_BEAM_DIA Beam diameter
LAS_PULSE_FREQ Pulse frequency
LAS_PULSE_WIDTH Pulse width
LAS_PULSE_ENERGY Pulse energy
LAS_DI_WATER_RES DI Water resistance
LAS_COOLANT_TEMP Coolant temperature
LAS_SECTOR_HGT Sector height
LAS_CT_POS CT Position
LAS_VSM1_POS VSM 1 Position
LAS_VSM2_POS VSM 2 Position

Output from $W5 consists of one line for each defined sector. The line contains sector number, sector width (ms), and sector height.

MTConnect®: Getting Real-time Visibility On Laser Processes

MTConnect® is a communication standard used in the manufacturing industry for reporting the current status of a machine tool. MTConnect is an open protocol for integrating machine data into various ERP and manufacturing floor software applications where real-time or near real-time information is being reported. MTConnect will not interfere with workpiece processing but rather streams machine parameters through the MTConnect agent to plant management software.

The standard strives toward supporting a plug-and-play environment to reduce the cost of integration associated with real-time machines status reporting. It is built upon more prevalent standards within the manufacturing and software industry. The MTConnect standard defines a common interface supporting the ability to transfer data via a standard protocol which includes:

  • A device identity (i.e. model number, serial number, calibration data, etc.).
  • The identity of all the independent components of the device.
  • A possible device’s design characteristics (i.e. axis length, maximum speeds, device thresholds, etc.).
  • Most importantly, data captured in real or near-real-time (i.e. current speed, position data, temperature data, program block, etc.) by a device that can be utilized by other devices or applications (e.g. utilized by maintenance diagnostic systems, management production information systems, CAM products, etc.).

The types of data that may need to be addressed in MTConnect includes:

  • Physical and actual device design data
  • Measurement or calibration data
  • Near-real-time data from the device

The S94P control supports MTConnect and will automatically connect to any MTConnect® reporting software package that requests a connection, and stream the current state of the machine to it. The process is designed to be seamless, with no input required from the machine operator.

The data stream may be monitored from the MTConnect screen in the Maint94P application (see figure 2).

The MTConnect® Screen

Figure 2: The MTConnect® Screen

The reporting software packages require setup files, which are unique to each machine. These files may be generated from the MTConnect screen by pressing the “Make Config File” and “Make Device File” buttons. The files are stored in the MTConnect subfolder in the c:\cnc-share\system folder.

The variables/parameters, which are streamed and through the agent are identified in Table 4. Any of these variables can be reported and used to help monitor and improve the laser processes.

Table 4 – Data Variables/Parameters

Data
Variable
Definition Units
Program
name
The name of the program in execution text string
Program
in operation state
If the machine is currently executing
a program (Ready/Active)
value
Program
running state
The current execution of the program
(Ready/Stopped/Active/Completed)
value
Machine
power on time
Accumulated
time of the machine running (processing a workpiece)
seconds
E-Stop
state
Has machine hit and maximum movement
of the axis.  (Value: Armed/Disarmed)
value
Control
ON state
State of the axis drives on/off
Program
name
The name of the program in execution text string
Program
in operation state
If the machine is currently executing
a program (Ready/Active)
value
Program
running state
The current execution of the program
(value states: Ready/Stopped/Active/Completed)
value
Program
checksum
The checksum of the NC text Hex Number
Axes
strokes (X, Y, Z, C, D, A, B, U)
The physical processing length of
each axis
(X, Y, Z) millimeters
(C, D, A, B, U) degrees
Axes
commanded positions
Commanded axis positions (X, Y, Z) millimeters
(C, D, A, B, U) degrees
Axes
actual positions
Actual axis positions (X, Y, Z) millimeters
(C, D, A, B, U) degrees
Feedrate
commanded
The commanded path speed millimeter/second
Feedrate
actual
The actual path speed millimeter/second
Feedrate
override
The current setting of the feed rate
override knob.
percentage
Laser
ready state
If the laser is ready for use on/off
Laser
shutter enabled state
If the laser shutter is enabled on/off
Laser
shutter state
The current state of laser shutter on/off
Laser
beam state
If the laser is creating a laser beam on/off
Laser
power commanded
Reports the commanded laser power
from the laser unit
watts
Laser
power actual
Reports the actual laser power from
the laser unit (measured by the laser unit at the input to the feed fiber)
watts
Gas
port states
The state of the gas ports on/off
Gas
pressure commanded
The commanded gas pressure at the gas
valve
pounds/inch2
Gas
pressure actual
The actual gas pressure at the gas
valve
pounds/inch2
Focus
sensor type
Which type of sensor is presently
enabled
AFC/OFC
Focus
sensor state
If the enabled sensor is active on/off
Focus
sensor position error
The sensor position error from
nominal
millimeters
Lens
number
The number of the selected lens integer
Error
numbers
The numbers of the active errors integer
Warning
numbers
The numbers of the active warnings integer

By using MTConnect to monitor a given set of machine parameters, one can gather real-time updates on job-status, run parameters, downtime, and machine information, which can be used to make the overall plant, machines, and maintenance more efficient.

MTConnect

Figure 3 – Typical connection for MTConnect®

 

If you are interested in the learning more about using MTConnect or SPC with your LASERDYNE® system, please contact lds.sales@primapower.com.

References: MTConnect Standard Parts 1-5, MTConnect Institute, March 2018
MTConnect is a registered trademark of AMT – Association for Manufacturing Technology.

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