Panasonic FPG Series Technical Manual page 15

FP∑ Positioning Unit Glossary
Positioning control start input (Timing input)
This is a JOG positioning operation input to transfer a JOG operation to a positioning operation. The
pulse count settings can be output after the external switch input.
Over limit input (+), Over limit input (-)
This is an input to set a limit the motor movement. Over limit input (+) is the maximum limit and Over
limit input(-) is the minimum limit.
Home return, Home search
The reference position for positioning is called a Home position and an operation to travel to a Home
position is called Home return. The home position should be set in advance. This operation moves to
the home position and its coordinate is set to be 0.
Home search automatically reverses the motor rotation when Over limit input(+) or Over limit input (-)
is input and searches the home position or the near home position to return to the home position
automatically.
Forced stop
This is function which interrupts the operation in progress, and stops it immediately. It is used to
initiate an emergency stop using an external switch, and to initiate a temporary stop through an
overrun.
Twisted pair cable
This refers to a cable constructed of two wires, which suppresses the effects of noise. Because
current of the same size is flowing in the reverse direction (the current in the same size flows in the
opposite direction between the two, noise is blanked out, which reduces the effects of the noise.
Home input
This refers to input of the reference position used for positioning, and is connected to the Z phase
signal of the servo motor driver, or to an external input switch and sensor.
Near home input
In order to stop the table at the home position, a position called the near home position is specified,
at which deceleration begins. This is connected to an external input switch or sensor.
Input valid logic
Depending on the type of sensor and switch connected to the home input and near home input, it is
necessary to confirm whether the input signal will be valid when current is flowing, or whether input
will be valid when no current is flowing. This is called the "input valid logic". With the FP∑ positioning
unit, this setting is entered using a control code in the program.
Deviation counter
This is located inside the servo motor driver, and counts the difference between command pulses
and the feedback from the encoder. Command pulses are counted as plus values and feedback
pulses are counted as negative values, with control being initiated so that the difference between
them is zero.
Deviation counter clear output signal
This is installed in the FP∑ positioning unit, and goes on when a home position return is completed,
to notify the driver that the table has arrived at the home position.
Pulser input operation
This is a device which generates pulses manually, and is used for adjustment when manual
operation is used. The same type of output as that from the encoder can be obtained, and the FP∑
positioning unit is equipped with a dedicated input terminal.
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