ABB 266 Operating Instruction page 68

266 Models - FOUNDATION Fieldbus
high and low range values of OUT_RANGE have no effect on the block.
Types of integration:
The value of OUT can start from zero and go up or it can start from a Setpoint value (TOTAL_SP) and go down. Reset may be
automatic, periodic, or on demand. This is defined by the enumerated parameter INTEG_TYPE:
– UP_AUTO Counts up with automatic reset when TOTAL_SP is reached
– UP_DEM Counts up with demand reset
– DN_AUTO Counts down with automatic reset when zero is reached
– DN_DEM Counts down with demand reset
– PERIODIC Counts up and is reset periodically according to CLOCK_PER
– DEMAND Counts up and is reset on demand
– PER&DEM Counts up and is reset periodically or on demand
The first four types indicate use as a batch totalizer with a setpoint TOTAL_SP. This is not the standard SP because it does not have the
structure of SP that is defined in FF-890. The count does not stop at TOTAL_SP going up or zero going down, as it is important to get
the true total of flow. Two outputs, OUT_TRIP and OUT_PTRIP, are associated with the four types. See Batch totalizer outputs below.
The next three types indicate that TOTAL_SP and the trip outputs are not used. The Periodic type (5) disables operator reset.
The internal registers always add the net increments. Counting down is done by setting OUT to the value of TOTAL_SP minus the most
significant part of Total.
Resetting the totals:
The block shall use a discrete input RESET_IN to reset the internal integration registers. The operator can send an operator command
to reset the same registers by making OP_CMD_INT = RESET. This is a momentary switch, which shall be turned off when the block is
evaluated. Either shall cause reset to occur. Reset should occur after the totals have been adjusted in the same block evaluation. The
block should take a snapshot of the most significant part of Total, Rtotal and TOTAL_SP just prior to the reset and move the values to
the registers STOTAL, SRTOTAL and SSP, respectively. The information should be kept until the next reset. The integrator should reject
reset requests for at least 5 seconds after a reset. This is to allow time for other devices to read the snapshot values before they can be
overwritten. 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. This provides a guarantee
that a host has recorded the snapshot values before the next reset can occur. The number of resets is counted in the register N_RESET.
This counter can not be written or reset. It provides verification that the total has not been reset since N_RESET was last checked. The
counter should roll over from 999999 to 0. 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. The option Generate reset
event in INTEG_OPTS shall cause an analog event (DS-75) to be generated at each reset. This messages provides a timestamp and the
most significant part of Total just prior to the reset. The Standard Type (4.3) shall be 14, Reset event. The Subcode (4.8) shall be the
status byte of OUT. The Value (4.9) shall be the most significant part of Total just prior to the reset. The Unit Index (4.11) shall be the
units code of OUT_RANGE.
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
then 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.
Configuration hints
The minimum configuration for having the IT working and/or moving out from the OOS needs at least the following settings:
– Set TIME_UNIT1 different by 0
– Set TIME_UNIT2 different by 0
– Set INTEG_TYPE different by 0
68 OI/266/FF/ADD-EN Rev. B | 2600T Series Pressure transmitters