SZGH SZGH-CNC1000MDb Series, Руководство пользователя

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-Shenzhen Guanhong Automation Co.,Ltd.- SZGH-CNC1000MDb Series
- 44 -
3.18 Inch/Metric Conversion (G20/G21)
Either inch or metric input can be selected by G code.
Format: G20 ; Inch input
G21 ; mm input
This G code must be specified in an independent block before setting the coordinate system at
the beginning of the program. After the G code for inch/metric conversion is specified, the unit of
input data is switched to the least inch or metric input increment of increment system IS
–
B or IS
–
C. The unit of data input for degrees remains unchanged.
The unit systems for the following values are changed after inch/metric conversion:

Feedrate commanded by F code

Positional command

Work zero point offset value

Tool compensation value

Unit of scale for manual pulse generator

Movement distance in incremental feed
Unit explanations for G20/G21
1.Min unit: 0.0001inch(G20/INCH); 0.001mm(G21/Metric)
2.Command unit of G20/INCH for Position command is inch.
3.Command unit of G20/INCH for Feeding Speed (F) command is inch/min.
4.Unit of G20/INCH for Tool Offset(Redeem)/G54-G59 offset value is inch.
5.Unit of G20/INCH for distance type parameter(like max travel,compensation value,...) will be
to 0.1inch from mm(G21/Metric) ; & change um(G21/Metric) to 0.0001inch(G20/INCH)
6.Unit of G20/INCH for speed type parameters will be to 0.1inch/min from mm/min(Metric).
7.INCH Unit for accelerate type parameters will be 0.1inch/min/s from mm/min/s(Metric)
8.Handwheel Increment(Rate) will be 0.0001inch(*1), 0.001inch(*10), 0.01inch(*100).
9.Pulse equivalent will be changed when G20/INCH,system will adjust automatically.Electric
Ratio is figured out with G21/Metric.
10.Coordinate display of G20/INCH is with 4bits data after dot.
11.Degree unit of G20/INCH is display with 0.1, also 1degree display with 0.1inch.
12.Shift mode between INCH/Metric: run G20/G21 on MDI,reboot CNC.
13. It needs to posit tool again after shift INCH/Metric mode.
When the power is turned on, the G code is the same as that held before the power was turned
off.
Note: 1. G20 and G21 must not be switched during a program.
2. Movement from the intermediate point is the same as that for manual reference position return.The direction
in which the tool moves from the intermediate point is the same as the reference position return direction.
3. When the least input increment and the least command increment systems are different, the maximum
error is half of the least command increment. This error is not accumulated.
4. The inch and metric input can also be switched using setting of data setting.
5. User can ask SZGH or agent/distributor for parameter display unit on CNC with INCH mode before
order.
6. Suggestion that keep one processing mode(Metric/INCH) on one CNC control system.