Encoder-Based Operational Hook Block Limits (Clv); Encoder-Based Limits Parameters (Clv) - Hitachi P1 Basic Instruction Manual

ENCODER-BASED OPERATIONAL HOOK BLOCK LIMITS (CLV)

The VFD has the capability to utilize the motor encoder to create digital upper and lower operational hook block limits. This is done
with the use of the encoder from the motor while operating in closed loop vector control only (AA121 = 10) and with the encoder-
based limits enabled (UE-33 = 1 or 2). The VFD will store the pulse data on power cycle. If power is removed during operation or the
motor is rotated without power on, the encoder limit areas may shift and may need to be reset. If an encoder fault occurs or the
VFD's control mode is changed from AA121 = 10 then encoder-based limits will need to be reset.
If an external rotary/geared limit is to be used for operational hook block limits you will need to disable this feature by setting
parameter (UE-33 = 0).
HOW IT WORKS – The encoder-based limit system utilizes an upper limit, upper limit approach zone, lower limit, and lower limit
approach zone. The upper and lower approach zones can be configured separately. The approach zones will limit the VFD's frequency
to low/1st speed and will ignore all other speed commands when traveling into the zone's direction. When traveling out of the
approach zones high speed commands will be allowed. The approach zones are used to prevent over travel through the upper and
lower limits when in high speed. The approach zones will automatically adjust when the VFD is operating in auto-speed.
Manual adjustments to the approach zone or stopping pulse count should be used with caution in which to prevent over travel. When
adjusting the deceleration time longer than the factory settings the approach zone pulse count and stopping pulse count may need to
be increased to prevent over travel.
If additional digital inputs are required for other functions, the factory program and reset terminal knife disconnect switches can be
disconnected and the encoder-based limits can be configured for parameter use UE-33 = 2. Make sure to change UE-33 = 2 before
removing the switches or the limits may need to be reset.

ENCODER-BASED LIMITS PARAMETERS (CLV)

Function
Encoder-Based Limits Mode
Limits Program Mode
* Only when UE-33 = 2
Upper Limit Approach Zone Pulse Count
Lower Limit Approach Zone Pulse Count
Pulse Count for Stopping
Parameters
UE-33
UE-66
UE-63
UE-64
UE-65
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Value
0 = Disabled
1 = Enabled Using External Switches
2 = Enabled Using Parameters
0 = Program Mode OFF
1 = Program Mode
2 = Program Mode with Position Reset
10240 pulses (default)
10240 pulses (default)
768 pulses (default)