HMR2300R

Magnetic Products Preliminary THREE-AXIS STRAPDOWN MAGNETOMETER FEATURES • Strapdown Magnetometer Replaces Bulky Fluxvalves • Microprocessor Based Smart Sensor • Range of ±2 Gauss—50,000 hours HMR2300r APPLICATIONS • Navigation Systems—Avionics and Marine • Fluxvalve Replacement • Can be Slaved to AHRS System • GPS Backup Systems • Remote Vehicle Monitoring • Unpiloted Air Vehicles (UAVs) • Navigation/Attitude for Satellites GENERAL DESCRIPTION Honeywell’s three-axis strapdown magnetometer detects the strength and direction of the earth’s magnetic field and communicates the x, y, and z component directly via serial bus. The HMR2300r is compliant with applicable MIL-STD810E requirements for military and commercial flight systems (see Table 6). It was designed to be a replacement for bulky fluxvalve magnetic sensors commonly used in aviation systems. The HMR2300r strapdown magnetometer provides an excellent replacement of conventional fluxvalve sensors, commonly used in aviation systems today. The HMR2300r offers higher reliability (MTBF >50,000 hours) that reduces maintenance and repair cost. Since the design is strapdown, as opposed to a gimballed fluxvalve, it has no moving parts to damage or wear out during severe flight conditions. Low cost, high sensitivity, fast response, small size, and reliability are advantages over mechanical or other magnetometer alternatives. With an extremely low magnetic field sensitivity and a user configurable command set, these sensors solve a variety of problems in custom applications. A command set is provided (see Table 4) to configure the data sample rate, output format, averaging and zero offset. An on-board EEPROM stores any configuration changes for next time power-up. In addition, the user has 55 bytes of EEPROM locations available for data storage. Other commands perform utility functions like baud rate, device ID and serial number. Also included in the HMR magnetometer is a digital filter with 50/60 Hz rejection to reduce ambient magnetic interference. A unique switching technique is applied to the solid-state magnetic sensors to eliminate the effects of past magnetic history. This technique cancels out the bridge offset as well as any offset introduced by the electronics. The data is serially output at either 9,600 or 19,200 baud, using the RS422 or RS-485 standard. The RS-485 standard allows connection of up to 32 devices on a single wire pair up to 4,000 feet in length. An HMR address can be stored in the on-board EEPROM to assign one of thirty-two unique ID codes to allow direct line access. An internal microcontroller handles the magnetic sensing, digital filtering, and all output communications eliminating the need for external trims and adjustments. Standard RS-422 or RS-485 drivers provide compliant electrical signalling. Solid State Electronics Center • 12001 State Highway 55, Plymouth, MN 55441 • (800) 323-8295 • http://www.ssec.honeywell.com HMR2300r OPERATING SPECIFICATIONS—Table 1 Characteristic Supply Voltage Supply Current Operating Temperature Storage Temperature Field Range Linearity Error Hysteresis Error Repeatability Error Gain Error Offset Error Accuracy Resolution Axis Alignment Noise level Temperature Effects Power Supply Effect Vibration (operating) Max. Exposed Field Weight Conditions Pin 9 referenced to pin 5 Vsupply=15V (with 120 Ω termination) Ambient Ambient, unbiased Full scale (FS)—total applied field Best fit straight line ±1 Gauss -40 -55 -2 0.1 1 0.01 0.05 0.05 0.01 0.12 1 67 ±1 0.07 -0.06 ±0.01 150 10 2.0 10 40 ±2 ±0.13 1 Gauss (G) = 1 Oersted (in air), 1G = 79.58 A/m 1G = 10E-4 Tesla, 1G = 10E5 gamma ppm - parts per million Min 6.5 Typ Max 15 Unit Volts mA °C °C Gauss %FS %FS %FS %FS %FS %FS µGauss degree mGauss %/° C ppm/V mm g force Gauss grams 45 55 85 125 +2 0.5 2 0.02 0.10 0.10 0.03 0.52 2 3 sweeps across ±2 Gauss @ 25 ° C 3 sweeps across ±2 Gauss @ 25 ° C Applied field for zero reading Applied field for zero reading RSS of all errors ±1 Gauss Applied field to change output Variation to 90 degrees Output variation in fixed field Coefficient of gain Coefficient of offset (with S/R=ON) From 6 to 15V with 1 Gauss applied 5 to 10Hz for 2 hrs. 10Hz to 2KHz for 30 min. No perming effect on zero reading Board only TIMING SPECIFICATIONS—Table 2 Characteristic Conditions Timing Diagrams (Figs. 1,2) *dd command (dd=Device ID) *ddP *ddRST *ddC *99 command (exceptions below) *ddQ *99Q Timing Diagram (Fig. 2) *99 comand (dd=Device ID) Timing Diagrams (Fig. 1) 9600 19200 28 Min 1.9 Typ 2.2 2.2 6 40 2 + (dd x 40) 2 + (dd x 80) 2 + (dd x 120) 2+ (dd x 40) 1.04 0.52 80 140 Max Unit TRESP 3.2 3.2 6.5 msec 60 2 + Typ 2 + Typ 2 + Typ 2 + Typ msec msec msec TDELAY TBYTE TSTARTUP Power Applied to start of Start-Up message 2 HMR2300r RS-485 and RS-422 COMMUNICATIONS—Figure 1 Start 4V LSB MSB Stop Timing is not to scale Hi 2V 1V 4V ... ... of Command TBYTE TRESP Lo 2V 1V HMR2300r Response GLOBAL ADDRESS (*99) DELAY—Figure 2 TRESP Timing is not to scale Command Bytes (*01P) HMR ID=01 Response (XXYYZZVC) TDELAY (ID=02) TDELAY (ID=01) TRESP Command Bytes (*99P) HMR ID=00 Response (XXYYZZVC) HMR ID=01 Response (XXYYZZVC) HMR ID=02 Response (XXYYZZVC) Sample Rate (sps) ASCII 9600 yes Binary 9600 yes f3dB (Hz) 17 17 21 26 34 42 51 Notch (Hz) 50/60 50/60 63/75 75/90 100/120 125/150 150/180 250/300 308/369 385/462 19200 yes 19200 yes Continuous Reading Period (msec) 10 20 25 30 40 50 60 100 123 154 101 51 41.5 35 24 19.6 16.1 9.8 8.1 6.5 DATA INVALID 85 104 131 Parameter Selections verses Output Sample Rate—Table 3 3 HMR2300r COMMAND INPUTS—Table 4 A simple command set is used to communicate with the HMR. These commands can be typed in through a standard keyboard while running any communications software such as HyperTerminal® in Windows®. Command Format Inputs (1) Response (2) Bytes(3) Description 9 10 9 or 28 ... 0 3 7 8 7 or 8 4 4 4 7 3 14 16 8 9 8 or 9 7 8 7 or 8 3 3 62-72 16 ASCII - Output readings in BCD ASCII format. Binary - Output signed 16 bit binary format. (default) P=Polled - Output a single sample. C=Continuous - Output readings at sample rate. (default) Escape key - Stop continuous readings. Set sample rate to nnn where: nnn= 10, 20, 25, 30, 40, 50, 60, 100, 123, or 154 samples/sec (default 30 sps) S/R mode: TN -> ON=automatic S/R pulses (default) TF -> OFF=manual S/R pulses ] character - single S/R: ]S -> SET=set pulse Toggle alternates between SET and RESET pulse. Read device ID (default ID=00) Set device ID where nn=00 to 98 Set baud rate to 9600 bps. Set baud rate to 19,200 bps. (default) (8 bits, no parity, 1 stop bit) Zero Reading will store and use current reading as a negative offset so that the output reads zero field *ddZR toggles command. (default=OFF) The average reading for the current sample X(N) is: Xavg = X(N)/2 + X(N-1)/4 + X(N-2)/8 + X(N-3)/16 + ... *ddV toggles command. (default=OFF) Turn the "Re-enter" error response ON (*ddY) or OFF (*ddN). OFF is recommended for RS-485 (default=ON) Read setup parameters. default: binary, Continuous, S/R ON, ZERO OFF, AVG OFF, R ON, ID=00, 30 sps Change all command parameter settings to factory default values. Change all command parameter settings to the last user stored values in the EEPROM. Output the HMR2300r serial number. Output the HMR2300r software version number. Output the HMR2300r hardware version number. Activate a write enable. This is required before commands like Set Device ID, Baud Rate, and others shown in table. This writes all parameter settings to EEPROM. These values will be automatically restored upon power-up. A command was not entered properly or 10 characters were typed after an asterisk (*) and before a . This error response indicates that this instruction requires a write enable command immediately before it. *ddWE *ddA *ddWE *ddB *ddC ASCII_ON ← BINARY_ON ← {x, y, z reading} {x, y, z stream} {stream stops} Output Sample Rate *ddWE *ddR=nnn OK ← *ddWE *ddTN *ddWE *ddTF *ddWE *ddT S/R_ON ← S/R_OFF ← {Toggle} SET ← RST ← {Toggle} ID=_n n ← OK ← OK ← BAUD=_9600 ← OK ← BAUD=_19,200 ← ZERO_ON ← ZERO_OFF ← {Toggle} AVG_ON ← AVG_OFF ← {Toggle} OK ← OK ← {see Description} *ddWE *ddD OK ← BAUD=_19,200 ← OK ← BAUD=_9600 or BAUD=_19,200 SER#_nnnn ← S/W_vers:_ nnnn ← H/W_vers:_ nnnn ← OK ← DONE ← OK ← Re-enter ← WE_OFF ← Set/Reset Mode Set/Reset Pulse *dd] Device ID *ddWE *ddID=nn *99WE *99!BR=S *99WE *99!BR=F *ddWE *ddZN *ddWE *ddZF *ddWE *ddZR *ddWE *ddVN *ddWE *ddVF *ddWE *ddV *ddWE *ddY *ddWE *ddN Baud Rate Zero Reading Average Readings Re-enter Response Query Setup Default Settings Restore Settings *ddWE *ddRST 14 16 22 27 19 3 Serial Number Software Version Hardware Version Write Enable *ddWE *dd# *ddF *ddH Store Parameters *ddWE *ddSP 8 9 7 Too Many Characters Wrong Entry Missing WE Entry Write Enable Off (1) All inputs must be followed by a carriage return, or Enter, key. Either upper or lower case letters may be used. The device ID (dd) is a decimal number between 00 and 99. Device ID=99 is a global address for all units. (2) The “←”symbol is a carriage return (hex 0D). The “_” symbol is a space (hex 20). The output response will be delayed from the end of the carriage return of the input string by 2 msec (typ.), unless the command was sent as a global device ID=99 (see TDELAY). 4 HMR2300r DATA FORMATS The HMR2300 transmits each x, y, and z axis as a 16-bit value. The output data format can either be 16-bit signed binary (sign + 15-bits) or binary coded decimal (BCD) ASCII characters. The command *ddA will select the ASCII format and *ddB will select the binary format. The order of output for the binary format is: Xhi, Xlo, Yhi, Ylo, Zhi, Zlo. The binary format is more efficient for a computer to interpret since only 9 bytes are transmitted. The BCD ASCII format is easiest for user interpretation but requires 28 bytes per reading. There are limitations on the sample rate based on the format and baud rate selected (see Table 3). Examples of both binary and BCD ASCII outputs are shown below for field values between ±2 Gauss. Field (Gauss) +2.0 +1.5 +1.0 +0.5 0.0 -0.5 -1.0 -1.5 -2.0 BCD ASCII Value 30,000 22,500 15,000 7,500 00 - 7,500 -15,000 -22,500 -30,000 Binary Value (Hex) High Byte 75 57 3A 1D 00 E2 C3 A8 8A Low Byte 30 E4 98 4C 00 B4 74 1C D0 The Validity byte indicates that the onboard microprocessor has properly executed code routines for the selected mode of operation. The various user selectable modes are shown in the table below with the corresponding validity byte and associated ASCII character. Zero Readings off off off off on on on on (1) Average Readings off off on on off off on on Auto Set/Reset off on off on off on off on Validity Character byte O 4F S (1) 53 O 4F V 56 P 50 T 54 P 50 W 57 Default mode. This mode can be reset using the *99we, *99rst command sequence. 28 bytes ASCII Format: SN | X1 | X2 | CM | X3 | X4 | X5 | SP | SP | SN | Y1 | Y2 | CM | Y3 | Y4 | Y5 | SP | SP | SN | Z1 | Z2 | CM | Z3 | Z4 | Z5 | SP | SP | Output Readings—Table 5 Binary Format: XH | The ASCII characters will be readable on a monitor as signed decimal numbers. This format is best when the user is interpreting the readings. = carriage return (Enter Key), Hex code = 0D SP = space, Hex code = 20 SN (sign) = - if negative, Hex code = 2D SP if positive, Hex code = 20 CM (comma) = , if leading digits are not zero, Hex code = 2C SP if leading digits are zero, Hex code = 20 X1, X2, X3, X4, X5 = Decimal equivalent ASCII digit X1, X2, X3 = SP if leading digits are zero, Hex code = 20 9 bytes XL | YH | YL | ZH | ZL | Validity | Checksum | XH = XL = YH = YL = ZH = ZL = Validity = Checksum= = signed high byte, x axis low byte, x axis signed high byte, y axis low byte, y axis signed high byte, z axis low byte, z axis Validity byte is described below Checksum is the ones complement of the sum of the first seven bytes carriage return (Enter Key), Hex code = 0D RS-232 to RS-485 B&B Electronics #485PTBR HMR2300r RS-422 Output data format is in counts (sign + 15 bit magnitude) Scale factor is 1 gauss = 15,000 counts Output measurement range = ± 30,000 counts RS-232 The binary characters will be unrecognizable on a monitor and will appear as strange symbols. This format is best when a computer is interpreting the readings. TD RD GD 2RD 3TD 7GD TD(A) TD(B) RD(A) RD(B) SG +12VDC TERM. Rx-lo Rx-hi Tx-lo Tx-hi Gnd Pwr 1 8 3 2 5 9 J1 Pin connector Checksum = ones complement of the sum (XH + XL + YH + YL + ZH + ZL + Validity) 120VAC +12VDC INTERFACE CONVERTER TO RS-232—FIGURE 3 5 HMR2300r DATA COMMUNICATIONS The RS-422 signals are balanced differential signals that can send and receive simultaneously (full-duplex). The RS485 signals are also balanced differential levels but the transmit and receive signals share the same two wires. This means that only one end of the transmission line can transmit data at a time and the other end must be in a receive mode (half-duplex). The RS-422 and RS-485 lines must be terminated at both ends with a 120 ohm resistor to reduce transmission errors. There are termination resistors built into the HMR2300r as shown in Figures 4 and 5. The signals being transmitted are not dependent on the absolute voltage level on either Lo or Hi but rather a difference voltage. That is, when a logic one is being transmitted, the Tx line will drive about 1.5 volts higher than the Rx line. For a logic zero, the Lo line will drive about 1.5 volts lower than the Hi line. This allows signals to be transmitted in a high noise environment, or over very long distances, where line loss may otherwise be a problem— typically 4,000 feet. These signals are also slew-rate limited for error-free transmission. The receiver has a common mode input range of -7 to +12 volts. The signal connections are shown in Figure 6. Note: When the HMR2300r is in a continuous read mode on the RS-485 bus, it may be necessary to enter several escape keys to stop the readings. If the computer taking the readings can detect a carriage return code and send the escape code immediately after it, then a systematic stop reading will occur. If an operator is trying to stop readings using the keyboard, then several (if not many) escape key entries must be given, since the RS-485 lines share the same wires for transmit and receive. If an escape key is entered during the time data is sent from the HMR2300r, then the two will produce an erroneous character that will not stop the data stream. The data stream stop only when the escape key is pressed during the time the HMR2300r is not transmitting. Computer D Z Rx-lo Rx-hi HMR Z R Tx-lo R Z Z=120Ω Tx-hi Z D RS-422 Balanced (full-duplex)—Figure 4 Computer D Z R Hi (B) Hi Lo (A) Lo HMR R Z D Z=120Ω RS-485 Balanced (half-duplex)—Figure 5 PINOUT DIAGRAMS—FIGURE 6 J1 Pins +6.5 to +15VDC power - 9 connected to P1 pin 6 - 7 +6.5 to +15VDC return - 5 Tx-lo (RS-422) or Lo (RS-485) - 3 Rx-lo (RS-422) - 1 P1 Sockets 10 - nc 10 - for manufacturers use only for manufacturers use only - 9 8 - Rx-hi (RS-422) 8 - for manufacturers use only nc - 7 6 - connected to P1 pin 2 6 - connected to J1 pin 7 +6.5 to +15VDC power - 5 4 - Chassis ground 4 - Chassis ground +6.5 to +15VDC return - 3 2 - Tx-hi (RS-422) or Hi (RS-485) 2 - connected to J1 pin 6 nc - 1 J1 Pin# 1 2 3 4 5 6 7 8 9 10 Pin Assignment Rx-lo (RS-422) Tx-hi (RS-422) or Hi(B) (RS-485) Tx-lo (RS-422) or Lo(A) (RS-485) Chassis ground +6.5 to +15VDC return connected to P1 pin 2 connected to P1 pin 6 Rx-hi (RS-422) +6.5 to +15VDC power (no connect) P1 Pin# 1 2 3 4 5 6 7 8 9 10 Pin Assignment (no connect) connected to J1 pin 6 +6.5 to +15VDC return Chassis ground +6.5 to +15VDC power connected to J1 pin 7 (no connect) for manufacturers use only for manufacturers use only for manufacturers use only 6 HMR2300r BOARD DIMENSIONS—FIGURE 7 All Dimensions in inches J1 TOP-SIDE OF CIRCUIT BOARD ASSEMBLY J1 SAMTEC TSW-105-06-T-D 10-PIN HEADER P1 SAMTEC SSQ-105-01-S-D 10-SOCKET HEADER P1 +Y +Z axis (Down) +X (FWD) .39 MAX COMPONENT HEIGHT .12 MAX .060 BACK-SIDE OF CIRCUIT BOARD ASSEMBLY COMPONENT HEIGHT 7 HMR2300r QUALITY AND ENVIRONMENTAL CONDITIONS—TABLE 6 Parameter Printed Circuit Board Assembly and Workmanship Electrostatic Sensitive Devices Method and Test Levels Conforms to IPC-6011 and IPC-6012, Class 3, using FR-4 laminates and prepreg per IPC-4101/21. Conforms to J-STD-001, Class 3, and IPC-A-610, Class 3, respectively. The HMR2300r shall be treated as an Electrostatic Sensitive Device (ESD) and precautionary handling and marking shall apply. Mean Time Between Failure (MTBF) The MTBF of the HMR2300r is 25,000 hours minimum under the environmental conditions specified. Altitude Fungus Shock The HMR2300r is capable of withstanding altitudes per MIL-STD-810E, Method 520.1, Procedure III. The HMR2300r is constructed with non-nutrient materials and will withstand, in both operation and storage conditions, exposure to fungus growth per MIL-STD-810E, Method 508.4 The HMR2300r will perform as specified following exposure to shock IAW MIL-STD-810E, Method 513.4, Table 516.4, Procedure I, V, and VI. Functional shock (20g, 11ms, 3 shocks in both directions of 3 axes) and crash hazard shock (40g, 11ms, 2 shocks in both directions of 3 axes. The HMR2300r will perform as specified during exposure to random vibration per MIL-STD-810E Method 514.4, Category 10, Figure 514.4, random vibration, 4 Hz - 2000 Hz (0.04g^2/Hz to 0.0015 g^2/Hz), 3 hr./axis operating. The HMR2300r, when clear coated, will operate as specified after 48 hrs. exposure to a salt atmosphere environment per MIL-STD-810E, Method 509.3, Procedure I *User must provide polyurethane clear coat to board. The HMR2300r will not ignite an explosive atmosphere when tested IAW MIL-STD-810E, Method 511.3, Procedure I. Method 507.3, Procedure III. 10 cycles at -54° C to +71 degC operating (approx. 4 hours/cycle including stabilization time). The HMR2300r will meet the requirements of MIL-STD-461C, Notice 2, and MIL-STD-462, Notice 5. Vibration Salt Fog* Explosive Atmosphere Humidity Temperature EMI APPLICATIONS PRECAUTIONS Several precautions should be observed when using magnetometers in general: • The presence of ferrous materials—such as nickel, iron, steel, cobalt—near the magnetometer will create disturbances in the earth’s magnetic field that will distort x, y and z field measurements. The presence of the earth’s magnetic field must be taken into account when measuring other x, y and z, fields. The variance of the earth’s magnetic field must be accounted for in different parts of the world. Differences in • the earth’s magnetic field are quite dramatic between North America, South America and the Equator region. Perming effects on the HMR board need to be taken into account. If the HMR board is exposed to fields greater than 10 Gauss (or 10 Oersted), then the board must be degaussed. The result of perming is a high zero field output code that may exceed specification limits. Degaussing devices are readily available from local electronics outlets and are inexpensive. If the HMR board is not degaussed, zero field offset values may result. • • ORDERING INFORMATION HMR2300r-422 HMR2300r-485 RS-422 Communication Standard RS-485 Communication Standard Customer Service Representative 1-800-238-1502 fax: (612) 954-2257 E-Mail: clr@mn14.ssec.honeywell.com Honeywell reserves the right to make changes to any products or technology herein to improve reliability, function or design. Honeywell does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. 900232 Rev. B 1/99