Honeywell HPM, Service

Page: 437 / 498

7 IOP Calibration Procedures
7.4 LLAI IOP Calibration Procedure
R688 HPM High-Performance Process Manager Service 437
December 2020 Honeywell
7.4 LLAI IOP Calibration Procedure
CAUTION
There is a risk of electric shock when performing the procedures in this section.
SHOCK HAZARD
Troubleshooting, opening this equipment and removing any panels or covers will expose the
user to the risk of a shock hazard. There are no user serviceable parts inside this equipment.
Refer all servicing only to qualified service personnel .
Seven ranges
The Low Level Analog Input has seven different ranges that require calibration on a per slot basis, and a
special range type for its reference junction calibration. At any one time, only one of the given gain
ranges is being used by a given slot. Each range usage is independent from another slot’s usage (for
example, performing a calibration for one range does not affect the calibration constants of another
range).
Calibration affects eight slots
Although the LLAI performs calibration on an individual slot basis, only calibration affecting all eight
slots can be performed.
Range type selection
Calibration of a slot assumes that the range type selected is applied to the slot. The range type is
internally derived from the slot’s current configuration of sensor type (
SENSRTYP
), PV character
(
PVCHAR
), and thermocouple range option (
TCRNGOPT
for a thermocouple input).
ATTENTION
The user is responsible for reconfiguration of the slots so that the input voltage or resistor
applied to each channel is appropriate for the configuration. Any violation, due to a
configuration mismatch during calibration, will result in calibration abort errors.
CAUTION
Although mixed ranges of calibration are allowed, never configure slot 1 as an RTD input if
there is at least one slot configured for a thermocouple. This is because the reference junction
for a thermocouple input is connected to slot 1.
Select RTD or TC calibration
When performing RTD calibration, all eight points must be configured as RTD. The same is true when
performing thermocouple calibration. All eight points must be configured as thermocouple.
Performing calibration sequences
CAUTION
When performing the following calibration sequences, be sure to use only high-quality solid
copper wire for all the wire jumpers and voltage source wires to the FTA’s inputs. Failure to use
high-quality solid copper wire can result in calibration errors and reduced accuracy.
An excellent source of high-quality solid copper wire is the copper wire conductor of type-T
thermocouple wire (usually color-coded blue).