BusWorks®
961/962PB Module User’s Manual ProfiBus Differential I/V Input
___________________________________________________________________
_______________________________________________________________________________________
Acromag, Inc. Tel:248-624-1541 Fax:248-624-9234 Email:
http://www.acromag.com
11
There are six calibration channels for these models. The following table
gives the calibration values for the input ranges of these models. These are
the input signals required to calibrate the range endpoints. Your success in
recalibrating the input will depend upon the accuracy and precision of your
signal source. Note that on the 961PB-2006, the 4-20mA range is a sub-
range of the 0-20mA range and is automatically calibrated at the same time.
If calibration is required, it is recommended that all ranges of the unit be
done.
IMPORTANT:
For best results, be sure to use a precision signal source
capable of reproducing the nominal endpoint signals shown below, at least
as accurate as the module itself (better than ±0.1% of span). Always allow
the module to warm up a few minutes prior to calibration.
RANGE
ZERO Calibration
FS Calibration
Model 961PB-2006
0-20mA DC, 4-20mA DC
1.0mA
20.0mA
0-11.17mA DC
1.0mA
11.17mA
0-1mA DC
0.25mA
1.00mA
Model 962PB-2006
±10V DC
-10000.0mV
10000.0mV
±5V DC
-5000.0mV
5000.0mV
±2.5V DC
-2500.0mV
2500.0mV
±1.25V DC
-1250.0mV
1250.0mV
±625mV DC
-625.0mV
625.0mV
±313mV DC
-312.50mV
312.50mV
±156mV DC
-156.25mV
156.25mV
±78mV DC
-78.13mV
78.13mV
These models have two I/O Configuration definitions in their GSD files,
one for normal operation, and another for accomplishing calibration. The
normal data exchange definition supports 6 input words (12 input bytes
representing your measured values). A second calibration definition
supports 6 input words and 6 output words. The master software will allow
you to choose which mode the slave will assume
—Input Mode or
Configuration Mode. The method used to transfer information between the
master and slave will vary widely between systems. The steps below
represent the minimum steps necessary to accomplish software calibration.
If you choose to perform calibration and select Configuration Mode, the
master will download the 6I/6O word configuration during the startup
sequence, and the module may then be calibrated as follows:
1. With your master software, select the “Configuration Mode” from the
GSD file when setting up the master to communicate with the module.
2. With user parameterization bytes 0 & 1, set the ranges that are to be
calibrated.
3. Apply the zero calibration signal (see table of prior page) to the input to
be calibrated and allow the input to settle a few seconds.
4. Write FFH into the low-order byte of the channe
l’s output word several
times (to ensure transmission). In Configuration Mode, the module will
automatically calibrate the channel’s zero value when FFH is detected.
Then write 00H into the low-order byte to complete zero calibration.
CALIBRATION
IMPORTANT:
This module
has already been calibrated at
the factory and recalibration is
not normally required, except
as necessary to correct for
long term component aging, or
to satisfy your company’s
maintenance requirements.
Do not attempt to recalibrate
this module unless absolutely
required, as miscalibration will
negatively affect the module’s
performance.
