Honeywell ST700 User Manual page 86

Resetting the totals
The block uses a discrete input RESET_IN to reset the internal integration registers. The
operator can send a command to reset the same registers by making OP_CMD_INT =
RESET. This is a momentary switch that turns-off when the block is evaluated. The option
"Confirm Reset" in INTEG_OPTS, if set, prevents another reset from occurring until the
value 1 has been written to RESET_CONFIRM. This is an input that behaves like a
momentary dynamic parameter if it is not connected.
The number of resets is counted in the register N_RESET. This counter cannot be written
or reset. It provides verification that the total has not been reset since N_RESET was last
checked. The counter must roll over from 999999 to 0.
The reset always clears the internal registers Total, Atotal, and Rtotal, except that when the
option UP_AUTO or DN_AUTO is selected, a residual value beyond the trip value may be
carried to the next integration if the option Carry is set in INTEG_OPTS. In this case,
TOTAL_SP is subtracted from Total, leaving the residual value.
Batch totalizer outputs
When the integration is counting up (type 1 or 2) and the value of OUT equals or exceeds a
value given by TOTAL_SP minus PRE_TRIP, the discrete output OUT_PTRIP is set.
When it equals or exceeds a value given by the parameter TOTAL_SP, the discrete output
OUT_TRIP is set. OUT_PTRIP remains set.
When the integration is counting down (type 3 or 4), it starts from a value given by
TOTAL_SP. When the value of OUT is equal to or less than PRE_TRIP, the discrete
output OUT_PTRIP is set. When the count reaches zero, the discrete output OUT_TRIP
is set. OUT_PTRIP remains set. When a reset occurs, the comparisons that set
OUT_PTRIP and OUT_TRIP are no longer True; so they are cleared. OUT_TRIP shall
remain set for five seconds after an automatic reset (type 1 or 3), if RESET_CONFIRM is
not connected or the option to Confirm Reset in INTEG_OPTS is not set.
ATTENTION
To determine the amount of Uncertain or Bad readings, the block integrates
the variables with Bad, or Bad and Uncertain status separately. The values
used in this second integration are the values with Good status, just before
the status changed from Good to Bad or Good to Uncertain.
The ratio of Good to total counts determines the output status. Absolute
values are used to avoid problems with changing signs.
Integration options
Any or all of the following integration options can be selected:
INTEG_OPTS: 0 (Input1 Accumulate)
When this option is selected, the accumulation of pulses is done instead of the rate input,
integration.
INTEG_OPTS: 0 (Input2 Accumulate)
When this option is selected, the accumulation of pulses is done instead of the rate input,
integration.
Page 72 FOUNDATION Fieldbus ST 700 Pressure Transmitter User's Guide Revision 2.0