Current Value And Flag For Monitoring Of Operation; Current Value - Mitsubishi Electric Melsec-F FX3GC Series User Manual

FX /FX /FX /FX /FX
3S 3G 3GC 3U 3UC
Built-in Positioning Functions
4.4

Current Value and Flag for Monitoring of Operation

4.4.1

Current Value

During positioning operation, use the current value register to check the current value positioning address.
The current value will be increased or decreased depending on the rotation direction. The following table
shows the current value register (32-bit) of each pulse output destination device.
Pulse output destination device
*1. Y002 is not available in FX
*2. Y003 is available only when two high-speed output special adapters are connected to the FX
Caution:
The current value changes between -2,147,483,648 and 2,147,483,647. However, if an overflow or underflow
occurs, the value changes as shown below. Check the value carefully.
• If the current value is increased past the maximum value, the minimum value will be indicated.
• If the current value is decreased below the minimum value, the maximum value will be indicated.
Necessity of zero return:
If the specified forward rotation pulse or reverse rotation pulse is output, the current value register will
increase or decrease the current value. Upon turning off the power of the PLC, however, the current value
stored in the current value register will be erased. For this reason, after turning the power on again, be sure to
adjust the current value of the current value register to the current position of the machine. For this
adjustment, use the zero return instruction or the Absolute Current Value Read instruction (absolute position
detection system) shown below:
Instruction
DSZR(FNC150)
ZRN(FNC156)
ABS(FNC155)
*3. The absolute position detection function applies for the MR-J4A, MR-J3A, MR-J2SA, MR-J2A,
or MR-HA servo amplifiers. If one of these servo amplifiers is used and mechanical zero return is
performed only once just before turning off the power, the current value will not be erased even after
power-off.
After turning on the power again, read out the stored current value using the ABS (FNC155)
instruction of the PLC. This means that the current value can be obtained without performing zero
return just after turning on the power again.
PLC User's Manual - Positioning Control Edition
Y000
Y001
*1
Y002
*2
Y003
PLC (14-point and 24-point type) and FX
3G
Zero return instruction with DOG search function
Zero return instruction (without DOG search function)
Absolute Current Value Read instruction
*3
4.4 Current Value and Flag for Monitoring of Operation
Current value register (32-bit)
D8341,D8340
D8351,D8350
D8361,D8360
D8371,D8370
For details on DSZR instruction, refer to Section 6.2.
For details on ZRN instruction, refer to Section 6.3.
For details on ABS instruction, refer to Chapter 7.
Description
4 Before Programming
/FX PLC.
3S 3GC
PLC.
3U
B - 65
A
B
Apx.