Frequency Measurement Mode - Mitsubishi Electric MELSEC-L02SCPU User Manual

8.5

Frequency Measurement Mode

This section describes settings and functions that become valid when "Frequency Measurement Mode" is selected for
"Operation Mode Setting". In this mode, the pulses input from phase A and phase B pulse input signals are counted,
and the frequency is automatically calculated from the pulses. The measured frequency value is written to the
specified device using the Frequency measurement instruction (ICFCNT1) ( Page 252, Section 8.10.1 (7)). The
following table shows I/O signals used in this mode.
Count source
1-phase
multiple of 1
(A phase only)
1-phase
multiple of 2
(A phase only)
1-phase
multiple of 1
A phase/B
1-phase
phase
multiple of 2
CW/CCW
2-phase
multiple of 1
2-phase
multiple of 2
2-phase
multiple of 4
*1 The signals can be used for other functions such as the general-purpose input except the interrupt input.
*2 The signals can be used for other functions such as the general-purpose input and output.
Note that the explanations in this section assume use of CH1. For the special relay, special register, and dedicated
instructions for CH2, refer to the following.
• Special relay and special register:  Page 240, Section 8.9 (2)
• Dedicated instructions:  Page 241, Section 8.10
220
Input signal
Phase A Phase B Phase Z
*1

*2



Function Latch counter
input signal input signal
*2 *2
 
: Wiring required, : Wiring not required
Output signal
Coincidence Coincidence
output No.1 signal output No.2 signal
*2

*2
