7
© 2022 S. Himmelstein and Company—all rights reserved. www.himmelstein.com
the com port using furnished software. Pin strapping is
accomplished by shorting the designated pin on the four
pin connector, to Analog Ground (Pin 2).
CW Cal:
Short Pin 3 to Pin 2
CCW Cal: Short Pin 4 to Pin 2
The calibration signal will remain on until the short is
released. For that reason it should be invoked while the
driveline torque is at zero; if locked-in torque is present,
break one of the shaft couplings. When the driveline
torque isn’t zero, the calibration signal will add algebra-
ically with the driveline torque.
Calibration can also be invoked from a remote computer
using the furnished software.
Equivalent calibration values, in engineering unit of
measure, are listed on the Calibration Certificate which
documents NIST traceability. Calibration values were
determined in S. Himmelstein and Company’s accredited*
(NVLAP Lab Code 200487-0) calibration laboratory. They
can also be accessed using the furnished software. The
user may perform a dead weight calibration and store the
results in memory, using furnished software. The original
cal data is archived.
or follow the accreditation link at
.
B.2.3.3 Torque Zeroing
TORQUE ZEROING SHOULD ONLY BE DONE WHEN
THE DRIVELINE TORQUE IS ZERO
. If locked-in torque is
present, break one of the shaft couplings to remove it.
The Torquemeter can be remotely zeroed by simultane-
ously strapping the CW and CCW Cal enable lines (Pins
3 & 4) to Pin 2, and holding that condition for five (5)
seconds. When this is done, any residual system offsets
will be removed.
Torque Zeroing can also be invoked from a remote
computer using the furnished software.
B.2.4 Speed Signal Connector
B.2.4.1 Zero Velocity (Code Z) Pickup
Code Z Zero Velocity Speed Pickups have three pin
connectors. They require external power (6 to 15VDC).
Connections are as follows:
Pin A
+Power In (6 to 15VDC)
Pin B
Output Signal (60 pulses/rev)
Pin C
Common
Zero Velocity Speed Pickups produce 60 pulses/revolu-
tion. The pulse amplitude is independent of speed and is
approximately equal to the external supply voltage. Code
Z pickups are
recommended for low speed service and for
electrically noisy environments
.
Replacement Code Z Pickups can be ordered from the
factory; P/N: 900-1007. Spare mating connectors can also
be ordered; P/N: 224-5361.
B.2.4.2 Standard (Code A) Pickup
Code A Standard Speed Pickups have two pin connectors.
They are self generating, i.e., they do not require external
power. Connections are as follows:
Pin A
Signal
Pin B
Signal
Standard Speed Pickups produce 60 pulses/revolution.
The pulse amplitude is approximately proportional to
shaft speed. Therefore, outputs are low at low speeds.
If
you must measure speeds below 100 rpm or, if you are in
an electrically noisy environment, you should use a Code
Z Pickup.
Replacement Code A Pickups can be ordered from the
factory; P/N: 900-1001. Spare mating connectors can also
be ordered; P/N: 224-3897.
B.2.5 Com Port Connector; 3 Pins
Torquemeters are shipped with a 20’ Sensor to PC cable.
The cable is made per Figure 5. If required, we can supply
a 50 foot cable. RS232 runs greater than 50 feet require a
repeater.
The Baud rate is fixed at 115,200. Eight data bits are used
without parity. Neither handshaking or an ID is employed.
If you wish to write your own software, see Appendix
IV for serial communication commands. Spare mating
connectors can be ordered; P/N: 320-1286. Call the factory
should you need a spare cable assembly.
Load Device
DAS/Controller
Machine Base
Drive Motor
Torquemeter
Earth Ground
Load Device
DAS/Controller
Machine Base
Drive Motor
Torquemeter
Figure 4. Examples of Incorrect Earth Grounding.
