PC3000 Complete Installation guide iss 12 - Elektro-Trading

4 Channel Analogue Input Module
General calibration scheme
9-12
All parameters associated with calibration are included in the Analog Input Module
function block (Analog_In or Analog_In_R).
Ensure that the displayed resolution on the Programming Station is adequate for the
range being calibrated. The ‘PC3000 User Guide - Part 1 Programming’ describes
the use of the FORMAT key to alter displayed resolution. As a general recommendation
set displayed resolution to 3 decimal places when carrying out calibration. Note
that display resolution may only be altered as part of the off-line configuration and
must be set prior to compiling the program.
The parameters associated with calibration are as follows:
Cal_Lo_P the lower of the two calibration input values e.g 5mV on the
50mV range
Cal_Hi_P the upper of the two calibration input values e.g 45mV on the
50mV range
Cal_CJC_P the calibration reference point for the cold junction sensor
Cal_Mode the mode of operation for the channel.
Normally, channel is in the Run state.
During calibration the states I/P_Hi and I/P_Lo
followed by Save are selected from the list
The parameter Input_Type is used to select the input range for which calibration is
required. The channel is calibrated when the calibration mode is changed from Run
(0) to I/P_Hi (2) or I/P_Lo (3).
Note: This is different to the calibration scheme for the 2 channel
card in which the change of calibration point causes calibration to
take place.
The input is averaged over 80 cycles and the input must be stable following a change
of calibration mode from Run (0) to I/P_Hi (2) or I/P_Lo(3).
It is recommended that the input is allowed to settle for a minimum of 5s following a
change in applied input voltage. Reset the pre and post-linearisation scalers and
offsets to 1 and 0 set Lin_Type to Linear (0) prior to calibration. The measured value
is displayed in units consistant with selected configuration, mV, V etc. Several
calibration dates appear within the Function Block parameter list; these are associated
with the date of calibration of each confioguration, low level, RTD and high
level.
Note: At the present time calibration dates are not supported.
If Input_Type is changed following calibration but prior to saving the new calibration
data, the calibration data which existed prior to the start of the calibration session will
be restored. (Aborted calibration - may be used as a means of leaving the calibration
process in the event of an error).
PC3000 Installation