7I49 MANUAL Six channel analog servo amp interface with resolver inputs V1.2 This page intentionally almost blank Table of Contents GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 HARDWARE CONFIGURATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 DEFAULT JUMPER LOCATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 CABLE POWER/P1 POWER SELECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 RESOLVER DRIVE SELECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 CONNECTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 CONNECTOR LOCATIONS AND DEFAULT JUMPERS . . . . . . . . . . . . . . . . . CONTROLLER CONNECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AUX 5V POWER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SERVO AMP/RESOLVER CONNECTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4 5 6 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 PWM RATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 AOUT STEP RESPONSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 RESOLVER DRIVE VOLTAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 RESOLVER WIRING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 RESOLVER FIRMWARE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 RESMOD REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 VELOCITY REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 POSITION REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 COMMAND REGISTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 DATA REGISTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 PARAMETER READ SEQUENCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 PARAMETER WRITE SEQUENCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 RESOLVER STATUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 RESOLVER FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 SETTING RESOLVER FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 RESOLVER TRACKING RATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 5V POWER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 ENABLE INPUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 ENABLE OUTPUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 ANALOG OUTPUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 DRAWINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 iii GENERAL DESCRIPTION The 7I49 is a daughtercard for Mesa’s Anything I/O FPGA cards. The 7I49 provides a six channel resolver interface with six additional +-10V analog outputs. The 7I49 is intended for applications that read standalone resolvers, as the 7I49 generates the resolver reference carrier. The 7I49 can be used with 1:1 and 1:2 transformation ratio resolvers. The 7I49 has approximately 14 bits of resolution and 12 bits of absolute accuracy. The 7I49 FPGA interface module allows velocity and absolute position readout from the host. The 7I49 has selectable carrier frequencies, from 2.5 KHz up to 10 KHz. Host position readout is updated at 256 times the resolver carrier frequency to reduce aliasing when host sampling is not synchronous with the carrier frequency. Velocity resolution is approximately 1 RPM with default filter parameters. The 7I49 uses a oversampling A-D followed by a tracking filter. Filter coefficients may be changed to trade off noise versus acceleration tracking ability. The controller connection is a 50 pin header that matches the pinout of the Mesa anything I/O series of cards. All resolver and analog I/O is via 3.5 MM pluggable screw terminal blocks. The 7I49 requires a single 5V power supply. 7I49 1 HARDWARE CONFIGURATION GENERAL Hardware setup jumper positions assume that the 7I49 card is oriented in an upright position, that is, with the 50 pin controller connector is on the left hand side, DEFAULT CONFIGURATION JUMPER FUNCTION DEFAULT SETTING W1 CABLE POWER SELECT RIGHT = CABLE POWER W2 RESOLVER DRIVE SELECT UP = CHAN 3,4,5 = FULL CABLE POWER/P1 POWER SELECTION The 7I49 can get its operating power from the flat FPGA cable or from P1. For testing with only 1 or 2 resolvers, cable power can be used. W1 selects whether cable power connects to the 7I49s 5V supply. If W1 is in the "RIGHT" position, cable power is selected. If W1 is in the "LEFT" position, external 5V power must be supplied via P1. RESOLVER DRIVE SELECT The reference sine wave for all resolver channels on the 7I49 comes from a single PDM source in the FPGA. To accommodate resolvers with different transformation ratios, the 7I49 has the option to lower the reference drive voltage on channels 3,4 and 5. Default 7I49 firmware setup assumes a standard 2:1 reference:output ratio. To accommodate 1:1 resolvers on some channels the reference drive voltage on the last three channels can be set to ½ of full scale if desired. When W2 is in the up position, channels 3, 4, and 5 have standard reference signal levels. When W2 is in the down position, channels 3, 4, and 5 have ½ scale reference signal levels. 7I49 2 CONNECTORS CONNECTOR LOCATIONS AND DEFAULT JUMPER POSITIONS 7I49 3 CONNECTORS CONTROLLER CONNECTOR 50 pin header connector J1 connects to the anything I/O card/motion controller. This can be a male 50 pin header on the top of the 7I49 card or a female 50 conductor header on the bottom side of the 7I49 depending on 7I49 model. Controller connector pin-out is as follows: PIN FUNCTION DIRECTION PIN FUNCTION DIRECTION 1 /ENA0 TO 7I49 25 PWM-0 TO 7I49 3 NC XX 27 PWM+1 TO 7I49 5 SPIDO0 FROM 7I49 29 PWM-1 TO 7I49 7 SPIDO1 FROM 7I49 31 PWM+2 TO 7I49 9 AMUX2 TO 7I49 33 PWM-2 TO 7I49 11 AMUX1 TO 7I49 35 PWM+3 TO 7I49 13 AMUX0 TO 7I49 37 PWM-3 TO 7I49 15 SPICLK TO 7I49 39 PWM+4 TO 7I49 17 SPICS TO 7I49 41 PWM-4 TO 7I49 19 REFPDM- TO 7I49 43 PWM+5 TO 7I49 21 REFPDM+ TO 7I49 45 PWM-5 TO 7I49 23 PWM+0 TO 7I49 47 /ENA1 TO 7I49 49 +5V PWR TO 7I49 Note: all even pins are grounded. AUX 5V POWER The 7I49 can get its 5V power from the FPGA cable or connector P1. Normally P1 should be used for power as the 5V current draw from 6 resolvers will exceed what the FPGA flat cable can deliver. Note that the 7I49 will only connect to P1 power if the cable 5V is present. PIN FUNCTION 1 5V 2 GND 7I49 4 CONNECTORS TERMINAL BLOCK SERVO AMP/RESOLVER CONNECTORS The 7I49's servo amplifier / encoder connectors (P2,P3, and P4 ) are 3.5MM 24 pin headers compatible with Phoenix style screw terminal blocks (supplied). Connector P4 has the I/O signals for channels 0 and 1: P4 PIN FUNCTION DIR 1 RESSIN0- TO 7I49 2 RESSIN0+ TO 7I49 3 RESCOS0- TO 7I49 4 RESCOS0+ TO 7I49 5 GND FROM 7I49 6 RESDRV0- FROM 7I49 7 RESDRV0+ FROM 7I49 8 GND FROM 7I49 9 RESSIN1- TO 7I49 10 RESSIN1+ TO 7I49 11 RESCOS1- TO 7I49 12 RESCOS1+ TO 7I49 13 GND FROM 7I49 14 RESDRV1- FROM 7I49 15 RESDRV1+ FROM 7I49 16 GND FROM 7I49 17 ENA0- FROM 7I49 18 ENA0+ FROM 7I49 19 GND0 FROM 7I49 20 AOUT0 FROM 7I49 21 ENA1- FROM 7I49 22 ENA1+ FROM 7I49 23 GND1 FROM 7I49 24 AOUT1 FROM 7I49 7I49 5 CONNECTORS TERMINAL BLOCK SERVO AMP/ENCODER CONNECTORS Connector P3 has the I/O signals for channels 2 and 3: P3 PIN FUNCTION DIR 1 RESSIN2- TO 7I49 2 RESSIN2+ TO 7I49 3 RESCOS2- TO 7I49 4 RESCOS2+ TO 7I49 5 GND FROM 7I49 6 RESDRV2- FROM 7I49 7 RESDRV2+ FROM 7I49 8 GND FROM 7I49 9 RESSIN3- TO 7I49 10 RESSIN3+ TO 7I49 11 RESCOS3- TO 7I49 12 RESCOS3+ TO 7I49 13 GND FROM 7I49 14 RESDRV3- FROM 7I49 15 RESDRV3+ FROM 7I49 16 GND FROM 7I49 17 ENA2- FROM 7I49 18 ENA2+ FROM 7I49 19 GND2 FROM 7I49 20 AOUT2 FROM 7I49 21 ENA3- FROM 7I49 22 ENA3+ FROM 7I49 23 GND3 FROM 7I49 24 AOUT3 FROM 7I49 7I49 6 CONNECTORS TERMINAL BLOCK SERVO AMP/ENCODER CONNECTORS Connector P2 has the I/O signals for channels 4 and 5: P2 PIN FUNCTION DIR 1 RESSIN4- TO 7I49 2 RESSIN4+ TO 7I49 3 RESCOS4- TO 7I49 4 RESCOS4+ TO 7I49 5 GND FROM 7I49 6 RESDRV4- FROM 7I49 7 RESDRV4+ FROM 7I49 8 GND FROM 7I49 9 RESSIN5- TO 7I49 10 RESSIN5+ TO 7I49 11 RESCOS5- TO 7I49 12 RESCOS5+ TO 7I49 13 GND FROM 7I49 14 RESDRV5- FROM 7I49 15 RESDRV5+ FROM 7I49 16 GND FROM 7I49 17 ENA4- FROM 7I49 18 ENA4+ FROM 7I49 19 GND4 FROM 7I49 20 AOUT4 FROM 7I49 21 ENA5- FROM 7I49 22 ENA5+ FROM 7I49 23 GND5 FROM 7I49 24 AOUT5 FROM 7I49 7I49 7 OPERATION PWM RATE The 7I49 is meant to operate with PWM rates from 24 KHz to 500 KHz. Operation at lower PWM rates will result in excessive output ripple, operation at higher PWM rates or with PDM with higher than 10 MHz base frequency will result in poor linearity. When used with HostMot2 firmware, the PWM generators should be set for UP/DOWN mode and the PWM frequency set for 24 KHz. AOUT STEP RESPONSE The 7I49 AOUT channels have a 5 pole PWM filter with an approximate 150 uSec time constant. This value is selected as a compromise between output ripple and settling time. This is much faster than most controlled devices and will not normally have any effect on loop stability or performance. The 7I49 can be assembled with different components if necessary to change this time constant. RESOLVER DRIVE VOLTAGE The 7I49 is intended to operate with common 2:1 transformation ratio resolvers. Default drive voltage is approximately 2V RMS which is suitable for most resolvers. The sine and cosine inputs expect an analog signal level of approximately 1V RMS, so a 2V RMS drive voltage will use the full A-D input range with 2:1 ratio resolvers. For other resolver ratios, the drive voltage can be lowered. If a mix of 2:1 and 1:1 resolvers must be supported, the 7I49 can supply ½ drive on channels 3, 4, and 5 (1V RMS), allowing 1:1 ratio resolvers to be connected to channels 3,4, and 5 and 2:1 ratio resolvers to be connected to channels 0, 1, and 2. Higher stepdown ratio resolvers can be used, but will result in low signal levels which will show up as increased position and velocity noise. 7I49 8 OPERATION RESOLVER WIRING Resolver signals are analog and susceptible to noise. The 7I49 has differential drive and sine/cos signaling to improve noise rejection. To take full advantage of the differential signaling, resolver wiring should always be done with individually shielded twisted pairs. One shielded pair is used for the drive signal (RESDRVx+ and RESDRVx-), one shielded pair for the sine signals (RESSINx+ and RESSINx-) and one shielded pair for the cosine signals (RESCOSx+ and RESCOSx-). Shields should be terminated only at the 7I49 end of the cable. RESOLVER FIRMWARE It is expected that the 7I49 with be operated with an "Anything I/O" card using the RESMOD firmware. The RESMOD firmware generates the reference sine wave for the resolvers, interfaces with the A-D chip on the 7I49 card, acquires oversampled sine and cosine data from this A-D synchronously with the reference sine wave and feeds the A-D data into a second order tracking filter that tracks the resolver position and velocity. The outputs of this filter are then presented to the host in 32 bit read only registers for velocity and position. The RESMOD firmware also allows access to internal parameters for fine tuning. The default settings should be fine for most 7I49 applications, but most parameters can be tuned suit different applications. RESMOD REGISTERS The RESMOD FPGA firmware communicates to the host via three global registers (COMMAND, DATA, and STATUS) and 12 per channel registers (POSITION and VELOCITY per channel). Note: If RESMOD defaults are satisfactory, there is no need to access the command or data registers as these are only for changing operational parameters and resolver frequency. VELOCITY REGISTERS There are six 32 bit velocity registers per RESMOD firmware module. Velocity scaling is resolver frequency dependent. Velocity scaling in RPM is: Velocity register*Carrier frequency*60 / 2^32 POSITION REGISTERS There are six position registers. Each register reads absolute position in turns/2^32. Scaling for degrees is: Position register*360/2^32 Note that there are no multi-turn counters, so the position register must be sampled frequently enough to guarantee that no turns are lost. 7I49 9 OPERATION COMMAND REGISTER The command register is where parameter read and write commands and setup commands are written. Host handshaking is done by polling the command register. When the RESMOD firmware is busy, the command register will be non-zero. Only when the command register is zero should a command be written. DATA REGISTER The data register is where parameter data is written to and read from, as part of a parameter read/write sequence. PARAMETER READ SEQUENCE Parameter read sequence is as follows: 1. Write command register with parameter address 2. Wait for command register to be = 0 3. Read parameter from data register PARAMETER WRITE SEQUENCE Parameter write sequence is as fiollows: 1. Write data register with parameter data 2. Write command register with parameter address Ored with 0x00008000 3. Wait for command register to be = 0 RESOLVER STATUS The status register of the RESMOD interface reports resolver status. Bits 0 though 5 in the status register indicate status of resolver channels 0 though 5. A 1 bit indicates an error in the corresponding channel and that the position and velocity of that channel are invalid. 7I49 10 OPERATION RESOLVER FREQUENCY The current RESMOD firmware can operate with 3 selectable resolver frequencies, ~2.5 KHz, ~5 KHz and ~10 KHz. Resolver frequency is selectable for the 7I49 card, not per channel, so if a mix of resolvers is used, a frequency that is acceptable to all resolvers must be chosen. The default frequency is ~10 KHz. Lower rates will result in lower noise, but more lag between physical motion and the readout position. Actual resolver frequency depends on the FPGA reference clock (CLOCKLOW) with the following relationship: ~10 KHz CLOCKLOW/5000 ~5 KHz CLOCKLOW/10000 ~2.5 KHz CLOCKLOW/20000 SETTING RESOLVER FREQUENCY The default resolver carrier frequency is ~10 KHz. Writing a 0x801, 0x802, or 0x803 command to RESMOD’s command register will set the resolver frequency to ~2.5 KHz, ~5 KHz and ~10 KHz respectively. RESOLVER TRACKING RATE The second order tracking filter will track velocities up to ½ turn per sample. This is 75,000 RPM at 2.5 KHz, 150,000 RPM at 5 KHz and 300,000 RPM at 10 KHz. Note that "speed voltage" and other effects will limit accuracy at very high speeds, so suggested maximum speeds are 1/10 of the tracking maximums, that is 7,500 RPM at 2.5 KHz, 15,000 RPM at 5 KHz and 30,000 RPM at 10 KHz. The second order filter will "lock" onto constant velocities with essentially zero error other than noise, but will lag the resolver rotor position when the resolver is accelerating. The amount of lag depends on the tracking filter tuning and resolver frequency. The tracking filter tuning allows a compromise between position and velocity noise and the ability of the tracking filter to follow rapid acceleration with minimum error. With the RESMOD tuning defaults and 10 KHz resolver frequency, the position lag is less than 1/4 degree with a 30,000 RPM/sec acceleration. In addition to the position delay under acceleration, there is a fixed delay of 1/(resolver carrier frequency) + ~25 uSec in the position output. This is due to the synchronous sampling of the carrier frequency plus a fixed processing time (the ~25 uSec). 7I49 11 OPERATION 5V POWER The 7I49 requires ~400 mA of 5V power for operation. Power for the 7I49 is normally supplied from P1 but can also be supplied via pin 49 of the 50 conductor controller cable when testing or when low power resolvers are used. ENABLE INPUTS There are two active low enable inputs on the 7I49 that come from the FPGA. When either of these enable inputs is high, all AOUTs are forced to 0V, and all enable outputs are turned off. Pullup resistors keep the enable inputs high if the controller connection is lost. ENABLE OUTPUTS Each 7I49 channel has a OPTO-isolated transistor output that can be used to enable external amplifiers. All six outputs are on when both input enable signals are low, that is all enable outputs are switched at once. Maximum switched voltage is 36VDC. Maximum output current is 10 mA. Even though all outputs are switched in common, they are all isolated to allow different enable connections on a per amplifier basis. Example connections: 1. Active high 12V amplifier enable on ch 0: Connect ENA0+ to +12V source Connect ENA0- to amplifier enable input 2. Active low TTL input Connect ENA2- to ground Connect ENA2+ to amplifier enable input ANALOG OUTPUT The analog output of the 7I49 swings from -10 v to +10V. Positive outputs are generated when PWM+ is input is driven, and negative outputs when PWM- is driven. A 50 % duty cycle PWM signal will generate a 5V output. This mode of operation requires the PWM generator be set for "up/down" mode The 7I49 has limited DC output drive capability and should not have loads of less than 2K Ohms on its analog outputs. 7I49 12 SPECIFICATIONS MIN MAX UNITS 5V POWER SUPPLY 4.75 5.25 VDC 5V POWER CONSUMPTION --- 400 mA ANALOG OUTPUT VOLTAGE +-9.8 +-10.2 V ANALOG OUTPUT STEP RESPONSE 120 160 uSec MINIMUM AOUT LOAD RESISTANCE 2K --- Ohm OUTPUT RIPPLE @ 24 KHZ PWM --- .1% % FS LINEARITY --- .1% % FS (no external load) (no missing codes, 13 bit resolution with 24 KHz PWM) ZERO OFFSET ERROR -10 +10 mV RESOLVER FREQUENCY 2.5 10 KHz RESOLVER RESOLUTION 12 --- Bits 11 --- Bits OPERATING TEMP. 0 +70 o OPERATING TEMP. (-I version) -40 +85 o OPERATION HUMIDITY 0 95% NON-COND Typically 14-15 bits with 2:1 resolvers RESOLVER ABSOLUTE ACCURACY Typically 12 bits +- resolver inaccuracies Can be trimmed C C 7I49 13 DRAWINGS 7I49 14