Torque Trak 20K Torque Telemetry System User’s Guide 869610-9
Contents 1 System Overview ...........................................................3 1.1 TX20K Transmitter...................................................4 1.2 RX20K Receiver ......................................................4 2 Features and Controls ...................................................5 2.1 RX20K Receiver ......................................................6 2.1.1 Connections ......................................................6 2.1.2 LED Indicators............................
This document is subject to change without prior notification. Binsfeld Engineering Inc. | 231-334-4383 www.binsfeld.com 869610-9_A2 Pg.
1 System Overview The TorqueTrak 20K Torque Telemetry System utilizes proven digital RF technology to transmit a single data signal (most typically from a strain gage) a distance of 10 feet (3 meters) or more depending on the environment. Up to 16 systems can operate simultaneously on independent channels. TX20K Transmitter: The TorqueTrak 20K is a robust, precision strain measurement instrument ideal for short-term data collection and diagnostic testing.
1.1 TX20K Transmitter High signal-to-noise ratio for excellent resolution Low temperature coefficient for accuracy from -40 to 85°C Wide power supply input range from 6 to 20VDC Power Standby mode to extend battery life Two on-board shunt calibration values Status Indicator light to assist in troubleshooting Circuit fully encapsulated Two different transmit modes; Block, and Stream.
2 Configurable input for optional speed sensor. Simple Configuration and Monitor PC software included as well as serial protocol information for digital interface to data acquisition systems. Features and Controls The TT20K is a dynamic torque measurement system designed for temporary installations. The TX20K Transmitter is mounted on the rotating shaft along with a strain gage(s) and battery. The RX20K Receiver is connected to the USB port of a PC.
application. A higher RF power level will allow for more reliable transmissions over longer distances or in noisy RF environments. The lower RF power levels will increase battery life longevity. The RX20K always operates at maximum allowable RF power level since it is not battery operated. 2.1 RX20K Receiver The Receiver module had no display or control buttons. Configuration is done through the USB connection with a PC using the included Configuration and Monitor software.
2.1.2 LED Indicators Starting with the upper left LED and moving clockwise, the indicators are RNG, RXD Data, USB Data, and RPM. During power-up initialization or after a system reset, the normal LED pattern has both USB Data and RPM LEDs OFF while RNG and RXD Data LEDs alternate being ON. The power-up initialization lasts for about 5 seconds followed by all LEDs being on solid for about 1 second then all turn OFF before beginning normal operation.
2.1.2.1 Range (RNG) LED The Range LED is ON solid green when torque values are being received from the TX20K and are within range. If no torque values are being received, the Range LED is OFF. If torque error value(s) are received, the Range LED flashes at a rate of 2Hz. If errors are received intermittently, the Range LED is retriggered OFF for a least one 250msec period.
2.1.2.2 RF Receive Data (RXD) LED The green RXD Data LED is retriggered ON for 20msec when a byte is received by the RF transceiver of the RX20K. If the 20msec ON duration expires before another byte is received, the RXD Data LED switches OFF until another byte is received. 2.1.2.3 USB Data LED The green USB Data LED turns ON at the start of a USB Data transmission from the RX20K to the host PC.
2.2.2 LED Indicator The TX20K has one green indicator LED that is ON solid when it is operating in any mode other than Standby with no problems detected. In Standby mode the LED is OFF to conserve battery power. 2.2.2.1 Input Signal Out of Range When the input (strain gage) signal is detected to be out of range, the indicator LED flashes five times per second (5Hz). 2.2.2.2 Low Battery Indication Below approximately 6.
The TX20K has seven user selectable input range settings from ±0.2 to ±20mV/V. The table below shows just the positive side. The transmitted signal sample has a maximum range of ±20000. This gives the output resolutions listed below for each range. Table 3, Input Ranges Input Range mV/V1 Input Range µe2 Output Resolution µe/lsb2 Output Resolution µV/V/lsb Output Shunt13 100µV/V Output Shunt23 1mV/V 0.2 100 0.005 0.010 10000 over-range 0.5 250 0.0125 0.025 4000 over-range 1 500 0.025 0.
each block is transmitted, the TX20K switches its transceiver to receive configuration commands from the RX20K. If a command is received before the next block needs to be sent, it is executed. If no command is received, the next sample block is transmitted at the scheduled interval. The TX20K always operates in this mode when it powers up. Because samples are buffered at the transmitter in block mode, they are delayed by between one and two block intervals before reaching the USB port of the PC.
2.2.5.3 Standby Mode This is the TX20K low power, sleep mode. It is used to conserve battery power between test sessions. No torque or status data is transmitted while in Standby Mode. The TX20K wakes from this mode every 15 seconds to see if the RX20K is sending Wake commands. If not, the TX20K goes back to sleep. If the TX20K receives a Wake command from the RX20K, it will wake and operate at same Block Mode baud/sample rate as when it was put to sleep.
2.2.7 Signal to Noise Ratio Below are the TX20K’s typical Signal to Noise Ratios at the different range settings and sample rates. Table 6, TX20K signal to noise ratios Input Range mV/V 50sps (dB) 500sps (dB) 5000sps (dB) 0.2 68 58 49 0.5 75 66 57 1 81 72 62 2 84 76 66 5 86 79 70 10 86 79 70 20 86 79 70 2.2.8 RF Power Level The TX20K RF transmission power level is user adjustable. There are four different levels that can be chosen depending on the specific application.
2.2.10 Power Consumption The following table shows typical power supply current draw for the stream mode. Table 7, TX20K current draw, stream mode, 250K baud, 5000 sps Power Supply (Vdc) Power supply current draw (mA) at the four RF power levels 1 2 3 4 6.0 33 36 39 43 8.0 26 28 30 33 12.0 21 22 24 26 20.0 19 20 21 22 2.2.11 Battery Life Below are typical battery life times for the different operating modes of the TX20K.
3 Product Safety WARNING! PERSONAL INJURY DO NOT USE this product as a safety or emergency stop device or in any application where failure of the product could result in personal injury. Failure to comply with these instructions could result in death or serious injury. The user assumes all risk and liability for the installation and operation of this equipment. Each application presents its own hazards. Typically, certain system components are strapped to a rotating shaft.
the field. The BS900 Bridge Simulator and 9V Battery Connector have been provided for this purpose. See section 4.2 Bench Testing for details. 4.1 Field Testing Although the settings of the TX20K can be changed during operation of the system, it is best to determine the appropriate Transmitter Gain setting for a given application prior to installation. Refer to Appendix B for the relevant calculations. 1.
Secure to shaft. NOTE: If testing will not begin for some time, put the TX20K in Standby mode to save battery life. The Status Indicator light will turn off. A fresh battery will last for several days in this mode. 4. Cut an appropriate length of 4-conductor ribbon cable (as short as practical to avoid unwanted electrical noise) and strip and tin ends. Solder to gage per Appendix C or gage manufacturer’s specification and make appropriate connections to the TX20K terminals. Secure loose cable to shaft. 5.
4.2 Bench Testing 1. Connect Receiver Antenna to Antenna connector on the rear panel of the RX20K Receiver. Position magnetic-mount antenna with element installed near the TX20K, typically within 10 feet (3 meters). 2. Use a USB A male to B male cable to connect the RX20K to a computer for power and communications. The TT20K Configuration and Monitoring LabVIEW program must already be installed on the computer as explained in the 818006-9 TT20K Configuration and Monitoring User's Guide.
5.2 RX20K to USB Host Block Messages Table 9 - RX20K to USB Host Block Message Format byte index byte variable, all variables start with USBmsg2host.name. Description 0 hdr.stx header start char, always 0x55 1 hdr.len # of bytes following this byte in the USB msg to the host (always even and ≥ 52). # of header bytes is fixed at 44 (not counting stx and len). # of sample bytes is normally 200 (100 16 bit samples) but could be some other even #.
byte index byte variable, all variables start with USBmsg2host.name. Description 2 hdr.
byte index byte variable, all variables start with USBmsg2host.name. Description 4 hdr.RFcomm RF data baud/sps; 0x77: 250K, 5000sps 0x74: 250K, 500sps (default) 0x71: 250K, 50sps 5 hdr.RFchan RF data channel index (ch# - 1), values 0x00 thru 0x0F 6 hdr.RxRFpwr RX RF xmit power setting, values 0x00 thru 0x0F 7 hdr.RxRFlevData RF xcvr receive signal strength while good data is being received. 8 hdr.
byte index byte variable, all variables start with USBmsg2host.name. Description 15 hdr.rpmRel (HB) high byte of block start to Speed input -edge time 16 hdr.spdShift Timer #right bit shift for Speed and Sync values. The upper nibble is the #bit shift for Sync. The lower nibble is the #bit shift for Speed. 17 hdr.seqID 8 bit running value that increments every msg. 18 hdr.opMode Block = 0, Stream = 1, Standby = 2 19 hdr.
byte index byte variable, all variables start with USBmsg2host.name. Description 20 hdr.exp[0] Expansion board type: 0x7f = none b7 – update expansion board configuration, flag This flag is used internally and always displays as '0'. See separate expansion board parameter tables for details of hdr.exp[0] through hdr.exp[7] 21 hdr.exp[1] Expansion board configuration bits that control hardware options. Changing this bytes triggers expansion board hardware configuration to change. ...
byte index byte variable, all variables start with USBmsg2host.name. Description 45 hdr.Debug1 (HB) high byte of Debug1 46 samp[0] (LB) sample 0 low byte 47 samp[0] (HB) sample 0 high byte (signed 16 bit) 48 samp[1] (LB) sample 1 low byte 49 samp[1] (HB) sample 1 high byte hdr.len - 10 samp[n-1] (LB) sample n-1 low byte hdr.len - 9 samp[n-1] (HB) sample n-1 high byte hdr.len - 8 samp[n] (LB) sample n low byte hdr.len - 7 samp[n] (HB) sample n high byte hdr.len - 6 TXstat.
byte index byte variable, all variables start with USBmsg2host.name. Description hdr.len - 3 TXstat.Shunt b0 is shunt1 status b1 is shunt2 status 0 = Off, 1 = On b7:b2 - unused hdr.len - 2 TXstat.RFpwr b3:b0 = Transmitter RF TX power level setting b7:b4 - unused hdr.len - 1 TXstat.
Table 10: Analog Output Expansion Board hdr.exp[ ] parameters hdr.exp[] byte index name inside program description [0] mEXtype b7 – update expansion board configuration flag. Always write to this index after all other necessary indexes have been written. When b7 of index 0 is written as a '1', it triggers the RX20K to process the data in the 8 expansion configuration bytes.
5.3 USB Host to RX20K Commands Table 11 - USB host to RX20K Command Format. Command Description byte0 byte1 cmd code Read checksums 0x40 byte 1 – 0x00 Forces bootloader checksum to be output in block header bytes Debug0 and program checksum to be output in Debug1 byte 2 not used (0x00) byte 1 – 0x01 Cancel pending save of non-volatile parameters (used during TX scan) byte 2 not used (0x00) byte2 byte3 chksum chksum This document is subject to change without prior notification. Binsfeld Engineering Inc.
Command Description Expansion board configuration byte 1 - Expansion board parameter index byte 2 - Expansion board parameter value byte0 cmd code 0x50 byte1 byte2 byte3 chksum chksum byte 1 - Index [0] is always the Expansion board type with a byte 2 value: 0xff = no expansion board 0x80 = analog output Valid index values are 0 through 7. Writing a value for index 0 with bit 7 of byte 2 set triggers updating the expansion board configuration.
Command Description Speed input configuration byte1 – Speed input configuration b7:b4 - #bits to right shift sync timer value. b3:b0 - #bits to right shift speed timer value. byte0 cmd code 0x60 byte1 byte2 byte3 chksum 0x00 chksum Speed timer measures the period between negative speed input edges. Sync timer measures the time from the start of the previous block message to the first negative speed input edge.
Command Description Receiver Input Source control byte 1 - Input source value (0 to 7) 0 - transmitter (default) 1 - forced output = +1/4FS 2 - forced output = +1/2FS 3 - forced output = +FS 4 - forced output = 0 5 - forced output = -1/4FS 6 - forced output = -1/2FS 7 - forced output = -FS byte0 cmd code 0x65 byte1 byte2 byte3 chksum 0x00 chksum value value value value value value value This document is subject to change without prior notification. Binsfeld Engineering Inc. | 231-334-4383 www.
Command Description Receiver RF communications byte0 cmd code 0x6a byte1 byte2 byte3 chksum chksum byte1 – Operational mode Block = 0, Stream = 1, Standby = 2 byte2 – Block and Standby Mode byte2 is same as System RF communications (both RX and TX) below (cmd code 0x9a) value baud samples/sec 0 (0x71) 250K 1 (0x74) 250K (default) 2 (0x77) 250K 50 500 5000 If already in standby, sending the standby command with the same byte2 value starts the wake process.
Command Description System control: byte1 - RFU byte2 1 = Reset TT20K Transmitter 2 = Reset TT20K System System RF channel control byte 1 – RF channel value to set (0 to 15) value = RF channel (1 to 16) - 1 byte0 cmd code 0x90 byte1 byte2 0x00 0x92 byte3 chksum chksum 0x00 chksum This document is subject to change without prior notification. Binsfeld Engineering Inc. | 231-334-4383 www.binsfeld.com 869610-9_A2 Pg.
Command Description System RF communications (both RX and TX) byte0 cmd code 0x9a byte1 byte2 byte3 chksum chksum byte1 – Low nibble: Operational mode Block = 0, Stream = 1, Standby =2 byte1 upper nibble – Stream mode: Duration value most significant 4 bits. Block: set to 0 Standby: set to 0xF byte2 – Block mode: value baud 0 (0x71) 250K 1 (0x74) 250K 2 (0x77) 250K samples/sec 50 500 (dflt) 5000 byte2 – Stream mode: Streaming duration value low 8 bits.
Command Description Transmitter shunt and range control byte1 bits, shunt control b7:b2, not used b1 – shunt 2, 0 = OFF, 1 = ON b0 – shunt 1, 0 = OFF, 1 = ON byte2, transmitter range value (mV/V * 1ue) 1 = 0.2 2 = 0.5 3=1 4=2 5=5 6 = 10 7 = 20 Transmitter RF power control byte 1 – RF power level to set (0 to 15) byte0 cmd code 0xa0 byte1 0xa1 byte2 byte3 chksum chksum 0x00 chksum Notes: The chksum value is the low byte of the sum of byte0, 1, and 2. The CmdAck and CmdNak bits in USBmsg2host.name.
Appendix A: System Specifications Description of system specifications. TX20K Transmitter Specifications Power input 6.0 ~ 20VDC Current draw See section 2.2.10 Antenna Internal Operating temperature range -40 to +85°C (Ultralife 9V lithium battery -40 to +60°C) Size 26w x 16h x 52 lg mm (1.03"w x 0.64"h x 2.03"lg) Weight 35g G force 3000Gs Operating Frequencies 902 ~ 928MHz band see RF channels in Table 1 Excitation voltage 3.0V, Precision reference: 0.1%, 20ppm/°C Excitation current 12.
Serial Output Digital communication protocol See paragraph 5 above. Speed sensor power 4.2V @ up to18mA. Current draw for the speed sensor adds to the system USB 5V current draw. Speed sensor signal input 10K ohm pull-up to 3.3V. Maximum input freq 10KHz Speed sensor example Spectec 0158M-2-2-2-1-5. There are many variations. www.spectecsensors.com Analog output board power Powered by the RX20K main board from USB 5V. Adds approximately 70mA plus maximum output load current.
Torque on Round Shafts Step 1: Calculate Full Scale Torque, TFS (ft-lb) The Full Scale Torque corresponds to a system output of 10 V. For a solid steel shaft, use the calculator on our website at www.binsfeld.com or use the simplified equation below: (1510.
TXconst VFS Transmitter constant = 2.5V Full Scale Output of System = 10 volts Poisson’s Ratio (0.30 for steel) This document is subject to change without prior notification. Binsfeld Engineering Inc. | 231-334-4383 www.binsfeld.com 869610-9_A2 Pg.
For example, given a solid steel shaft with: DO (shaft Outer Diameter, measured) = 3.000 inches GF (Gage Factor from gage package) = 2.08 GXMT (TX10K Gain setting) = 4000 (1510.38 x 103 ft-lb/in3)(3.000 in)3 TFS = ────────────────────── = 4,901 ft-lb (2.08) (4000) so 10 V output from the RX20K indicates 4,901 ft-lb of torque or 490.1 ft-lb/volt. Step 2: Scale the Full Scale Output If desired, the Full Scale voltage output of the TX20K can be scaled so that it corresponds to a convenient torque value, e.g.
4,901 ft-lb ─────── = Z = 0.9802 5,000 ft-lb Next, multiply the Scale Factor times the Transmitter Gain setting to find the System Gain setting. 4000 x 0.9802 = 3920 Scroll to the Gain parameter screen on the RX20K and set the System Gain to 3920. In summary: Before adjusting full scale output: 4,901 ft-lb = 10.000 V (490.1 ft-lb/volt) After adjusting full scale output: 5,000 ft-lb = 10.000 V (500.
Shunt Calibration The more common method is to perform a shunt calibration. This method takes into account deviations in the setup from the strain gage to the transmitter, but unlike a deadweight calibration, none of the deviations in the physical parameters. The easiest way to conduct a shunt calibration is by enabling one of the reference shunt resistors on-board the TX20K. An internal precision resistor is placed in parallel with one arm of the bridge to simulate a precise strain value.
VS = VS εS εFS Z VFS εS ── (Z)(VFS) εFS Legend of Terms Voltage Output with Shunt Applied (V) Strain Simulated by Shunt (µe, GF = 2.0) Full Scale Strain (µe, GF = 2.0) Scale Factor (one if no scaling) Full Scale Voltage Output (V) (10V) In this example, with Reference 1 applied, the calibrated Voltage Output would be calculated as follows: 100 µe ───── (0.9802) (10 V) = VS = 1.9604 V 500 µe Adjust the System Gain setting until the output matches this value. The adjustment is typically small (<0.5%).
Appendix C: Strain Gage Installation View BEI’s online Strain Gage Installation Training videos at www.binsfeld.com/torquetrak/torquetrak-revolution/training-videos.html (Also refer to instruction bulletin B-127-12 provided with GAK-2-200 Strain Gage Application Kit from Vishay Measurements Group, Inc., Raleigh, NC, 919-365-3800, www.measurementsgroup.com.) PREPARING THE SURFACE 1. A 3-inch square area will be used for gaging. Scrape off any paint or other coatings and inspect shaft for oil residue.
PREPARING THE GAGE FOR MOUNTING 5. Using tweezers, remove one gage from its package. Using the plastic gage box as a clean surface, place the gage on it, bonding side down. Take a 6” piece of PCT-2M Mylar Tape and place it on the gage and terminal, centered. Slowly lift the tape at a shallow angle. You should now have the gage attached to the tape. POSITIONING THE GAGE 6.
when glue is applied. Very little catalyst is needed. Lift the brush cap out and wipe excess on lip of bottle. Use just enough catalyst to wet gage surface. Before proceeding, allow catalyst to dry at least one minute under normal ambient conditions of + 75F and 30-65% relative humidity. NOTE: The next three steps must be completed in sequence within 3 – 5 seconds. Read through instructions before proceeding so there will be no delays.
WIRING THE GAGE 13. Tin each solder pad with a solder dot. (It is helpful to polish the solder tabs, e.g. with a fiberglass scratch brush or mild abrasive, before soldering.) Trim and tin the ends of the 4-conductor ribbon wire. Solder the lead wires to the gage by placing the tinned lead onto the solder dot and pressing it down with the hot soldering iron. Note: For single-stamp torque gages, a short jumper is required between solder pads 2 and 4 as shown in the diagram on the next page 14.
16. Figure 2, Strain gage wiring This document is subject to change without prior notification. Binsfeld Engineering Inc. | 231-334-4383 www.binsfeld.com 869610-9_A2 Pg.
Warranty and Service Information Limited Warranty Binsfeld Engineering Inc. warrants that its products will be free from defective material and workmanship for a period of one year from the date of delivery to the original purchaser and that its products will conform to specifications and standards published by Binsfeld Engineering Inc. Upon evaluation by Binsfeld Engineering Inc., any product found to be defective will be replaced or repaired at the sole discretion of Binsfeld Engineering Inc.
FCC Rules Part 15: Computing Devices This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications.
