WAGO I/O-SYSTEM 750, Руководство пользователя по установке и настройке

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236 • I/O modules
Incremental-encoder interface 750-631
Modular I/O System
ETHERNET TCP/IP
Bit Function
CFAST_M Fast mode operation. Only the counter module function will be operable. All
other control bits will be ignored.
CNT_SET The counter module will be preset to a count value with a rising edge.
EN_LATEXT 0 =The external latch input is deactivated.
0 to 1=The module will latch in the counter data on the first rising edge.
Other changes have no effect.
EN_LACT 0 =Latching data with the Index pulse is deactivated.
0 to 1=The Index pulse will latch in the counter data on the first rising edge.
Other changes have no effect.
The status byte contains the information as listed below.
Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
0 x x OVER-
FLOW
UNDER-
FLOW
CNTSET_ACC LATEXT_VAL LATC_VAL
0 x x Counter
Overflow
Counter
Underflow
Counter Set
Acknowledge
External Latch
Acknowledge
Latch Data
Set
Bit Function
OVERFLOW The Overflow bit will be set if the counter value rolls over from 65535 to
0. This bit will automatically be reset if the counter passes through more
than one third of the count range, 21845 to 21846, or if an Underflow
occurs.
UNDERFLOW The Underflow bit will be set if the counter value rolls back from 65535 to
0. This bit will automatically be reset if the counter passes through more
than two thirds of the count range, 43690 to 43689, or if an Overflow
occurs.
CNTSET_ACC The Counter Set Acknowledge bit is set when a valid counter value is
preset to the module.
LATEXT_VAL The Latch External Valid Acknowledge bit is set when a counter value is
latched into the module via the Latch input.
LACT_VAL The Latch Index Pulse Valid Acknowledge bit is set when a counter value
is latched into the module via the Index pulse.
It is possible to process and/or check the actions listed below via the con-
trol and status bits
Extending the 16 bit counting range:
The internal counting range is 16 bits or a maximum value of 65535. Should
the application require an extended count range the location-difference-
integration method may be employed. This method uses the control system to
store the encoder module value. Any new encoder value will have the pre-
viously stored encoder value subtracted from it. This value will then be added
to an accumulated register value. It is assumed that the encoder value diffe-
rence of the two encoder values is smaller than 16 bits therefore overflows
need not be considered.
Another method calculates the extended encoder range via the underflow and
overflow status bits. The encoder value is either added or subtracted to the ac-