Mesa 8I20 User Manual
8I20 THREE PHASE MOTOR DRIVE MANUAL
V1.9
CAUTION!
THE 8I20 USES VOLTAGE AND POWER LEVELS THAT REPRESENT
A HAZARD TO LIFE AND LIMB.
THE 8I20 IS INTENDED FOR USE BY OEMS THAT WILL
INTEGRATE IT INTO A SYSTEM WITH INTERLOCKS AND OTHER
SAFETY FEATURES TO PREVENT USERS FROM CONTACTING
HAZARDOUS POTENTIALS OR BEING INJURED BY MECHANISMS
POWERED BY THE 8I20.
WHEN CHANGING JUMPERS OR OTHER OPERATIONS THAT
REQUIRE PHYSICAL CONTACT TO THE 8I20 CARD:
1. DISCONNECT MOTOR POWER AT THE 8I20
2. DISCONNECT MOTOR U,V,W AT AT THE 8I20. EVEN WITH NO
POWER APPLIED TO THE 8I20, A SPINNING SERVO MOTOR CAN
GENERATE LETHAL VOLTAGES.
3. WAIT 5 MINUTES FOR ON CARD MOTOR POWER CAPACITORS
TO DISCHARGE.
WHEN TESTING THE 8I20 ON THE BENCH IT IS SUGGESTED TO
AT THE MINIMUM:
1. CONNECT THE 8I20'S CHASSIS GROUND CONNECTION TO A
SECURE BUILDING GROUND.
2. USE A ISOLATED MOTOR POWER SUPPLY
3. TEST FIRST WITH A LOW VOLTAGE MOTOR POWER SUPPLY
4. TAKE EXTREME CARE WITH SERVO SYSTEMS, EXPECT THEM
TO RUN_AWAY WHEN FIRST TESTED.
Table of Contents
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
HARDWARE CONFIGURATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
LOGIC POWER SOURCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
SETUP/OPERATE MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
SERIAL PORT TERMINATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
CONNECTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
CONNECTOR LOCATIONS AND DEFAULT JUMPER POSITIONS . . . . . . . . 3
MOTOR/POWER/BRAKE CONNECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
LOGIC POWER/FAULT CONNECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
RS-422 SERIAL CONNECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
LOGIC POWER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
MOTOR POWER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
MOTOR BRAKE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
MOTOR CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
ENABLE INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
FAULT OUTPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
FAULT CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
CLEARING FAULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
FAULT MASK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
STATUS REGISTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
STATUS LEDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
HEATSINKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
DRIVE PARAMETER SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
PC HOST ADAPTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
SETUP COMMUNICATION WITH 8I20 . . . . . . . . . . . . . . . . . . . . . . . . 12
WPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
RPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
MAIN DRIVE SETUP PARAMETERS . . . . . . . . . . . . . . . . . . . . . . . . . 13
MAXCURRENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
BRAKEONV and BRAKEOFFV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
OPERATE MODE BAUD RATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
CURRENT LOOP TUNING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
iii
Table of Contents
CONTROLLERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
MULTI AXIS CONTROLLERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
HOSTMOT2 8I20 INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
SOFTDMC 8I20 INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
ANYTHING I/O INTERFACE DAUGHTER CARDS . . . . . . . . . . . . . . . 16
REFERENCE INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
HEATSINK PLATE DRAWING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
LBP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
LBP DATA READ/WRITEWCOMMAND . . . . . . . . . . . . . . . . . . . . . . . 20
EXAMPLE COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
LOCAL LBP COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
LOCAL LBP READ COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
LOCAL LBP WRITE COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
RPC COMMANDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
EXAMPLE RPC COMMAND LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
CRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
8I20 PARAMETERS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
SSLBP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
REGISTER MAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
PROCESSOR INTERFACE REGISTERS . . . . . . . . . . . . . . . . . . . . . . 30
COMMAND REGISTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
DATA REGISTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
LOCAL READ OPERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
LOCAL WRITE OPERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
NORMAL START . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
8I20 DEVICE SPECIFIC SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
STOP LBP INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
STOP INDIVIDUAL CHANNELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
DOIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
INTERFACE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
CS REGISTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
INTERFACE REGISTER 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8I20 SPECIFIC INTERFACE REGISTER 0 DEFINITIONS . . . . . . . . . 34
INTERFACE REGISTER 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8I20 SPECIFIC INTERFACE REGISTER 1 DEFINITIONS . . . . . . . . . 34
NORMAL MODE OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
SETUP START . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
SETUP MODE OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
iv
GENERAL
DESCRIPTION
The 8I20 is a low cost 2200W 400V three phase torque mode/voltage mode
amplifier for synchronous permanent magnet servo motors (Brushless AC servo) up to
approximately 3HP. The 8I20 will supply peak currents of 30A.
High side logic and gate power are derived from the low side allowing a wide
operational bus voltage range (24 to 400VDC) and host communication when bus voltage
is off. Low side power can be 5V +-5% or 8-40 V unregulated. 3750V RMS isolation is
provided between high and low side electronics. Hall effect current sensing is used along
with high speed bus voltage monitoring for an accurate, stable, and fast current/torque
control loop.
Host communications are provided by a low overhead 2.5 Mbps serial protocol over
isolated RS-422 link. Link speed allows up to 5 KHz update rates from host.
High side over current sensing protects the IGBT module from line-line and
line-ground faults. A brake output capable of 15A drive is provided. The brake output can
be driven at a presettable overvoltage setting.
Even though it uses a 40 MIPs DSP, the 8I20 is a 'dumb' amplifier suitable for
integration in host based motion control systems. The 8I20 requires reference angle and
requested current/torque or voltage values sent from a host controller. The 8I20 uses the
requested torque and reference angle to control the current loop. The 8I20 can echo status
information to the host controller including bus voltage, phase currents, card temperature,
and other parameters..
Both smart (SoftDMC) and host based (HostMot2) multi axiscontrollers are available
for the 8I20. Up to 32 axis of motion can be controlled by a single low cost FPGA based
controller.
8I20 1
HARDWARE CONFIGURATION
GENERAL
Hardware setup jumper positions assume that the 8I20 card is oriented in an upright
position, that is, with the I/O and power connectora towards the top of the card, away from
the person doing the configuration;.
LOGIC POWER SOURCE
The 8I20's logic power can be supplied via the serial cable or via pluggable terminal
block TB1. Jumper W2 determines the power source,
W2 MODE
UP Logic side power from serial cable (5VDC)
DOWN Logic side power from TB1 (7 to 48VDC)
SETUP/OPERATE MODE
The 8I20 can run in setup mode or operate mode. In setup mode, the serial
interface baud rate is fixed at 115.2 KBaud and the motor drive circuits are disabled. In the
operate mode, the baud rate is set to 2.5 Mbaud (default) and the motor drive circuitry is
enabled. Setup mode is enabled to allow normal PC serial ports or USB serial adaptors
to communicate with the 8I20 for setup purposes. W6 controls the setup/normal mode
selection.
W6 MODE BAUD RATE
UP Operate mode 2.5 Mbps (default, can be changed)
DOWN Setup Mode 115.2 Kbps (fixed)
SERIAL PORT TERMINATION
The RS-422 serial port on the 8I20 can be terminated or un-terminated. Normally
the 8I20 is the serial cable endpoint so the port must be terminated. If the 8I20 is used with
other devices on a shared RS-422 interface, the 8I20 should only be terminated if it is the
last physical device on the RS-422 cable. W4 and W5 enable and disable the termination
W4,W5 MODE
UP,UP Terminated (default)
DOWN.DOWN Unterminated
8I20 2
CONNECTORS
8I20 CONNECTOR LOCATIONS AND DEFAULT JUMPER POSITIONS
8I20 3
CONNECTORS
MOTOR - POWER - BRAKE CONNECTORS
The motor, motor power and brake connections are brought out on .250" spade
terminals on the top edge of the 8I20 card. From left t right the terminal functions are:
1 Chassis Gnd
2 Brake resistor 3 Brake resistor +
4 Motor power +
5 Motor power 6 Motor W
7 Motor V
8 Motor U
9 Chassis Gnd
LOGIC POWER/FAULT CONNECTOR
TB1 is the logic power/ fault output/enable input connector. TB1 is a six terminal 3.5
mm pluggable screw terminal block. TB1 pinout is as follows:
1 Unregulated logic power +
2 Unregulated Logic power 3 Enable in +
4 Enable in 5 Fault out +
6 Fault out -
8I20 4
CONNECTORS
SERIAL PORT
J1 is the 8I20s serial interface. J1 is a RJ-45 jack. The serial interface pinout is
compatible with standard 8 wire CAT5 Ethernet cables. J1 pinout is as follows:
1 RXA
2 RXB
3 TXA
4 GND
5 GND
6 TXB
7 +5V
8 +5V
J1s pinout is designed to match breakout cards like the 7I44. A standard CAT5 or
CAT5E cable can be used to connect the 8I20 to a 7I44. CAT5E cable is suggested if the
serial cable is used for powering the 8I20, as the larger wire size result in lower voltage
drop.
8I20 5
OPERATION
LOGIC POWER
All logic on the 8I20 runs from 5V logic power. This can be supplied over the serial
cable, or via a on card 5V regulator. Jumper W2 determines the logic power source. When
jumper W2 is in the ‘UP’ position, 5V logic power is suppled by the serial cable. Due to
voltage drop in the serial cable. The 8I20 should only be powered via the serial cable when
serial cable length is 8 feet or less. Typical 5V power consumption is 350 mA.
Logic power can also be supplied via the on card regulator and TB1. When W2 is
in the DOWN position, logic power comes from the on card regulator which is fed by TB1.
Unregulated power to TB1 pins 1 and 2 is regulated to 5V logic power. Unregulated input
to TB1 pins 1 and 2 can range from 8 to 40 VDC
MOTOR POWER
Motor power is supplied to the 8I20 via spade lugs #4 and #5. Motor power can
range from 35 to 400 VDC. All communication to the 8I20 will work down to 0V motor
power but the under-voltage fault setting will prevent motor operation at lower then ~35
VDC unless the default setting is changed. Default over-voltage fault is set for 385 VDC.
Voltages high that 385VDC will result in a overvoltage fault.
The 8I20 has local high frequency bypassing but relies on the power supplies output
capacitors to supply dc power with less than ~15% ripple. The 8I20 also relies on power
supply output capacitors to store motor inductive energy. For this reason, power should not
be disconnected from the 8I20 power input terminals when in operation. The 8I20 motor
power leads should use 18 GA wire and must be shorter than 3 feet. That is, motor power
should not be routed more than 3 feet from the main power supply filter capacitors. Power
supply circuit breakers or fuses should be located on the power supply primary, not
between the 8I20 and power supply capacitors.
MOTOR BRAKE
To prevent regenerated motor power from creating a over-voltage condition, the
8I20 can dump regenerated motor power into a user supplied brake resistor. The brake
circuitry can provide a maximum of 15 amps of braking current. At the maximum BrakeOn
setting of 385 VDC, this equals a ~25 Ohm resistor for maximum braking current.
Actual brake on/off voltages are programmable. Default brake on voltage is 360
VDC and default brake off voltage is 340 VDC. BrakeOn voltage must always be set higher
than BrakeOff voltage.
In addition to the programmable brake voltage settings, there is a fixed 385V
BrakeOn setting that cannot be changed. This is for 8I20 module protection.
8I20 6
OPERATION
MOTOR CONNECTIONS
The U/V/W motor connections are the direct PWM outputs of the 8I20s bridge.
Larger motors may have enough winding to frame capacitance to generate considerable
ground noise. This noise source can be reduced by:
1. Make sure that the motor frame ground signal is returned to the frame ground on the
8I20 card.
2. Use a ferrite bead as a common mode choke around all phase wires, that is the U/V/W
motor wires pass through a single bead. Do not route the frame ground wire through the
bead. A suggested ferrite bead is: Laird-Signal Integrity Products 28B1122-100.
ENABLE INPUT
The 8I20 has a isolated 4-24V enable input. This input must be driven to enable
motor drive. If enable input is not driven, the 8I20 will go into a fault state, and turn off
motor PWM.
FAULT OUTPUT
The fault output is an isolated transistor (OPTO coupler) output. The fault output is
off in non-masked fault conditions and on in normal operation. The fault output can supply
a maximum of 5 mA of output current and will switch voltages up to 24 VDC. Normally the
fault outputs of all 8I20s would be wired in series.
FAULT CONDITIONS
The 8I20 monitors many parameters and reports fault conditions in the FAULT
register. When a non-masked fault occurs, the 8I20 turns off motor drive and the current
control loop. The following is a list of the fault conditions:
NAME BIT FUNCTION
WATCHDOGFAULT 0 Communication timeout fault
NOENABLEFAULT 1 No external enable fault
OVERTEMPFAULT 2 8I20 PCB temperature > 85C
CURRENTFAULT 4 8I20 high side overcurrent Fault
8I20 7
OPERATION
FAULT CONDITIONS
NAME BIT FUNCTION
ULOOPCURRENTFAULT 5 U current >125% of MAXCURRENT
VLOOPCURRENTFAULT 6 V current >125% of MAXCURRENT
WLOOPCURRENTFAULT 7 W current >125% of MAXCURRENT
BUSLOVFAULT 8 Low motor voltage fault
BUSHIVFAULT 9 High motor voltage fault (settable)
MAXBUSVFAULT 10 High motor voltage fault (fixed at 400V)
MODULEFAULT 11 Module over temperature or low gate
OERRFAULT 14 8I20 serial port overrun error
voltage
FERRFAULT 15 8I20 serial port framing error
CLEARING FAULTS
Faults can not be cleared by writing the fault register but are cleared by setting the
CLEARFAULT flag. The host must then poll the state of CLEARFAULT until it is zero.
FAULT MASK
Certain faults can be masked so that they do not affect the external fault output.
Currently only the BUSLOVFAULT is maskable. A zero bit in the FAULTMASK register will
mask the corresponding fault bit.
8I20 8
OPERATION
STATUS REGISTER
The 8I20 maintains a status register that reflects various internal 8I20 conditions.
NAME BIT FUNCTION
ILIMITEDSTATUS 0 Indicates that MAXCURRENT is not
BRAKESTATUS 1 Current brake on status
BRAKEWASONSTATUS 2 Brake has been applied status (sticky)
WDTO 4 DSP startup due to Hardware watchdog
SWR 5 DSP startup due to software reset (sticky)
EXTR 6 DSP startup due to external reset (sticky)
available due to 8I20 temperature/current
limiting.
timeout (sticky)
Sticky status bits remember events until low side power is removed or the status
register is cleared.
8I20 9
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