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2. Modes of Operation
008-0738-00
Assuming that the factory calibrated (or user re-calibrated) data tables can be accessed using
the CAL user mode of the TMS Toolkit, the output calibration can be determined using this
theoretical method, an example of which will be given later.
Actual values can be determined by measurement and can be affected by power supply levels
and component tolerances.
When the TMS Toolkit is not available, the user will need to perform a physical system
calibration by placing a known torque on the sensor and measuring the change in the analog
output voltage.
In cases where the SHUNT CALibration value is known, the change in output due to SHUNT
CALibration can be measured and the result extrapolated to give a full scale equivalent. Note
that this result will need to be adjusted when the SHUNT CAL scaling feature has been used
(#SCSCALE is something other than 1). An example of calculating the analog output voltage
by using SHUNT CAL and the #SCSCALE parameter is given below.
Normal mode and FASTMODE data update rates
The table below provides a quick reference to the data rates available in either of two available
modes.
Mode
NORMAL
NORMAL
FASTMODE
Examples
The following examples assume that either the TMS Toolkit is available and running in CAL
user mode, or that a hard copy of the parameters list is available and valid.
Example 1 – Theoretical Determination of Analog Output Value
The relationship between torque and digital counts can be determined by reference to the
parameters held in the TMS 9250. When in FASTMODE, the digital counts received from the
rotor are simply piped through to the analog voltage output channel, so the counts
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© 2012 – Honeywell International Inc. All rights reserved
Note:
Due to the fact that the analog voltage output channel DAC is being
driven directly, the factory calibration of the output voltage is also
bypassed. This results in a maximum output voltage swing of
approximately -12.5 to +12.5 V, instead of the normal -10.0 to
+10.0.
When FILTSTEPS>1, data rate is 1104 results per second
When FILTSTEPS=1, data rate is 2207 results per second
8828 results per second
Note:
The analog voltage output channel shall be the only channel
in use for any data rate above 1104 results per second.
Therefore OPTYPE should be set to 1.
Any traffic on the RS-232 port caused by TMS Toolkit or any
other communications package will disrupt the flow of data
due to the interrupts that are generated by the external
software.
TMS 9250 Product User Manual
Data rate
Rev B
April 2012
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