Strain Gage Reaction Torquemeters Installation Guide
S. Himmelstein and Company
© 2017 S. Himmelstein and Company—all rights reserved www.himmelstein.com
5
assuming they act singly. Crosstalk errors from those loads are
typically 1% to 2% and, assuming they are constant, can be electri-
cally canceled.
W
= weight of test item
F
= thrust force, if any
d
= distance to test item center of gravity
Wxd
= bending moment
B. Electrical Installation
B.1 Signal Polarity
B.1.1 Definition of Torque Direction
A clockwise (CW) torque is defined as one that will cause shaft
rotation in the CW direction when viewed from the driven end. A
counterclockwise (CCW) torque will cause CCW shaft rotation
when viewed from the driven end.
B.1.2 Output Signal Polarity (Applies to all Models)
With CCW torque applied to the torquemeter, the output signal
is positive. When CW torque is applied to the torquemeter, the
output signal is negative. This assignment can be changed using the
furnished software.
B.2 Torquemeter Connections
Figure 9
shows recommended cabling when connected to a PC
and the users’ Data Acquisition System.
Pin Function
1
+ Calibration
1,6
2
RXD
3
Analog Ground
5
4
TXD
5
Analog Data Out 10.000V
2
at Rated Torque
6
Tare
3,4,6
7
+ Power Input (10 to 26 VDC)
8
Power Return
5
A mating connector with strain relief and boot is furnished. Use P/N 320-1306
to order additional connectors.
Notes
1.
Invoke bi-directional cals via the com port with furnished software.
2.
May be re-scaled via com port with furnished software to any value from
1 to 10V.
3.
Clear Tare via com port with furnished software; see Note 8.
4.
Tare and Clear Tare functions are also available via com port.
5.
Don’t use Pin 8 for analog data return and don’t use Pin 3 for Power
Return.
6.
Zero torquemeter via com port with furnished software or, by
simultaneously grounding pins 1 and 6.
7.
Stored Maxima and Minima can be re-set with the furnished software.
8.
Cycling Power off/on will Clear Tare and Reset Max/Mins but will not
change the Zero Setting.
To 9 Pin ‘D’
Connector
of Computer
COM Port
or
USB to RS232
Adapter (P/N 330-0002)
To
Data Acquisition
System
and
Power Supply
(10-26Vdc)
Belden 8777
or equivalent
Belden 8723
or equivalent
Earth Ground
Reaction Torquemeter Connector
+Power In
Power Return
Analog Output
Analog Ground
+CAL
Tare
Pin 7
Pin 8
Pin 5
Pin 3
Pin 1
Pin 6
Pin 4 TXD
Pin 2 RXD
Pin 8 GND
RXD
TXD
GND
Pin 2
Pin 3
Pin 5
Notes:
•
To adjust Zero, connect pins 1 and 6 to
pin 8 for 5 seconds.
•
To invoke a Positive CAL Check,
cCAL (pin 1) to GND (pin 8).
•
To Tare the current torque to zero,
connect Tare (pin 6) to GND (pin 8).
•
Cycling power will clear Tare and Reset
Max/Mins but won’t change the Zero setting.
•
Above functions may be invoked from
computer using supplied software.
Notes:
•
All cables are shielded.
•
Shields Float at Torquemeter end.
•
Shields terminated at Data Acquisition end.
•
Shield must be continuous. Do not cut
or splice them.
•
Body of Torquemeter should be strapped
to earth ground. See ¶B.3.
1
2
3
4
5
6
7
8
Figure 9.Connections Showing Analog Output Driving Data Acquisition System and Digital Output Driving a PC
