Rockwell Automation 57C421B Pulsetach Input Module/DCS 5000/AutoMax User Manual
Page 32

4Ć10
will always count up; however, the FORWARD and REVERSE LEDs
will flicker.
Bit: 9
Description: Inhibit Counter
Bit 9 is used to stop the counter from counting. When this bit is set
to one, the counter will not count incoming pulses. Note that this bit
is also set internally by the module when an external count stop
interrupt occurs (see register 5, bit 9). This bit must be reset after an
external count interrupt is generated to enable the module to count
again.
Bit: 10
Description: Origin/Clear Select
Bit 10 is used to specify the action that occurs when the origin/clear
input is true. If bit 10 is equal to one, the origin/clear input will reset
the counter whenever it is in the same state as the value specified
by register 6, bit 13. If bit 10 is equal to zero, the counter will be
reset when: the origin/clear input is in the same state as the value
specified by register 6, bit 13, the counter is counting in the direction
specified by register 6, bits 2 or 3, and the marker (Z) pulse occurs.
The latter is typically used to initialize the absolute position of a
machine.
Bit: 11
Description: Z Pulse Polarity
Bit 11 is used to specify the polarity of the Z pulse. If bit 11 is zero
(default), the Z pulse's logic is positive. If bit 11 is one, the pulse's
logic is negative.
Bit: 12
Description: Count Stop Input Select
Bit 12 is used to specify when the count stop input is considered to
be true. If this bit is zero, a high input signal (+V) will be considered
to be true. If this bit is one, a low input signal (0V) will be considered
to be true.
Bit: 13
Description: Origin/Clear Input Select
Bit 13 is used to specify when the origin/clear input is considered to
be true. If this bit is zero, a high input signal (+V) will be considered
to be true. If this bit is one, a low input signal (0V) will be considered
to be true.
Bit: 14
Description: External Latch Input Select
Bit 14 is used to specify when the external latch input is considered
to be true. If this bit is zero, a high input signal (+V) will be
considered to be true. If this bit is one, a low input signal (0V) will be
considered to be true.
Bit: 15
Description: Reset Counter
Bit 15 is used to reset the 24Ćbit counter under software control. The
counter is reset to zero whenever this bit is set.