Current Value - Mitsubishi MELSEC-F FX3U Series User Manual

FX /FX Series PLC User's Manual - Positioning Control Edition
3U 3UC
Built-in Positioning Function
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. 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 (Y000, Y001, Y002, Y003).
Pulse output destination device
*1. Devices related to Y003 (pulse output destination) are valid only if two FX
connected to the FX
Caution:
The current value will be counted in the range of -2,147,483,648 to 2,147,483,647. If the current value
exceeds this range, the following value will be indicated. Be careful not to exceed the later range.
• 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 the reverse rotation pulse is output, the current value register will
increase or reduce 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)
*2. The absolute position detection function is adopted for the MR-H A, MR-J2 A MR-J2S A, or MR-
J3 A servo amplifiers. If one of these servo amplifiers is adopted 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 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.
Y000
Y001
Y002
*1
Y003
PLC.
3U
Zero return instruction with DOG search function
Zero return instruction (without DOG search function)
Absolute Current Value Read instruction
*2
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
-2HSY-ADP adapters are
3U
B - 43
A
B
Apx.