The K520 is ExtraTech's current motion processing controller board. It is used in conjunction with an appropriate interface board (M20, M41K or M54). The K520 is based on an AMD SC520 main processor and a Motorola DSP 56F803 peripheral processor.
The controller is capable of coordinated motion on 4 axes. It can interface to digital servo or stepper motors that accept step and direction inputs. Excellent solutions can be creaed for plotters, engravers, routers, rotarty-knife cutters, laser cutters or marking systems, and water jet cutting systems. Special application processes with one or more axes for vertical or rotational motion are available.
The K520 is equipped with a variety of connectivity options. Two RS-232 serial ports provide conventional support for keypad and PC access. A 10-baseT ethernet port provides for a wide variety of devices and variations in user and controller locations. An EIA-485 Modbus® port provides compatibility with other industrial control and I/O devices. Two user analog inputs which are fed into digital converters provide additional flexibility for creation of custom solutions.
The K520 has many times the computing and control capacity of its predecessor. This controller excels in high speed, continuous motion at speeds much faster than typical machine tools.
Advanced Options for K520
There is an SBX expansion bus on the controller board. This is a modular, I/O expansion bus capable of increasing a base board's functional capability and performance. It provides a structure to attach small SBX boards. The standard connector supports 8 bidirectional data lines, 2 board (chip) select lines, a read line, a write line, an interrupt line and 5 address lines. +5V power is routed up the connector. The board is memory mapped from the CPU, so it can run at fairly high speeds. DMA lines are specified on the connector, however the K520 board does not support DMA operations.
The K520 also contains an FPGA that is programmed after power-up via firmware. An application with advanced requirements could take advantage of this in-circuit flexibility for additional application requirements.
Physical Layout
The K520 motion control board is 7 1/4 by 8 inches and has 9 mounting holes for mounting the
interface board (M20, M41k or
M54). The mounting holes are designed
for use with stand-offs. To see component positions, see the Physical
Layout page.
There are no external power or motion connections on the controller board itself. The controller
connects to the interface board through a 64 pin DIN connector at the edge of the board.
The interface board either sets beside and plugs directly into the controller, or it mounts on
top of the controller and is connected by a short ribbon cable. Power, motor control, position,
and other I/O connections reside on the interface board. Motor drive connections could reside on
an additional motor driver board.
LED Indicators
When the power is switched on, the POWER BAD LED will come on briefly as the board powers up.
Once the voltage is verified by the power monitoring software, the TXD YELLOW LED should blink
as the firmware boots up. Once the controller is running, the COM POWER LED should be on, one of
the CTS LED's should be on, and the TXD GREEN LED should be on most of the time.
Combinations of LED's that indicate a failure: COM POWER LED faint or off indicates the NME DC
to DC converter has failed or there is a short. Both CTS LED's off (one or the other should be
on) indicates the 202 driver has failed or there is a short in cable/receiver PC. TXD YELLOW not
blinking during BOOT-UP indicates 202 driver failure or short in cable/receiver. TXD GREEN not
on most of the time indicates the 202 driver has failed or there is a short in the cable/receiver.
VERTEX LED steady on indicates that the system is stuck in the interrupt routine or there is some
other failure of motion. PAUSE blinking and firmware not booting uCito indicates that the memory
test has failed. POWER BAD repeating a series of rapid blinks indicates voltage low or high (see
details just under the table below).
The following table lists the LED functions, normal operating behavior, and failure indications:
| LED label | Typical Operation | Failure Mode |
|
COM PWR Green |
Com Power - On means isolated +5V for serial channel present. |
Off, or faint, then NME DC-DC conv. failed or there is a short. |
|
RXD Yellow |
Receive Data - Blinks when EIA-232 characters received. |
|
|
CTS Red |
Stop Clear to Send - On when controller blocks telling host NOT to send. |
Both CTS LED's OFF then 202 driver failure or short in cable/receiver PC |
|
CTS Green |
Go Clear to Send - On when controller ready to receive characters. |
Both CTS LED's OFF then 202 driver failure or short in cable/receiver PC |
|
TXD Yellow |
Transmit Data - Blinks when controller is transmitting characters. |
NOT blinking during boot-up 202 driver has failed or short on cable/receiver. |
|
TXD Green |
TXD Pump - On steady transmitter charge pump is in proper state. |
If NOT mostly on 202 driver has failed or a short on cable/receiver. |
|
E-TXT Green |
Ethernet Transmit - Blinks when packet transmitted. |
|
|
E-RCV Green |
Ethernet Receive - Blinks when packet received. |
|
|
VERTEX Red |
Vertex Interrupt - Blinks during motion interrupt, vel./angle change (corner). |
Steady on would mean stuck in interrupt routine or other failure of motion. |
|
PAUSE Yellow |
Job Pause - On when machine velocity slowed or stopped (PAUSED). |
Blinking before boot-up and uCito not booted. Memory test has failed |
|
ALT Yellow |
Alternate Channel - On when ethernet connected and monitored. |
|
|
PWR BAD Red |
Power Bad - Off if voltage okay after boot-up. On steady during RESET. |
Blink 2-5 times repeated See description below for blink codes. |
Power Bad Blink Code -- LED will blink 2 to 5 times repeatedly if VCC is out of limits.
| 2 times repeatedly - BOOT-UP voltage LOW - adjust voltage to continue. |
| 3 times repeatedly - BOOT-UP voltage HIGH - adjust voltage to continue. |
| 4 times repeatedly - RUNNING voltage LOW - adjust voltage and re-boot board. |
| 5 times repeatedly - RUNNING voltage HIGH - adjust voltage and re-boot board. |
Power Requirements -- On K520 boards, power monitoring software will not allow the controller
to boot until VCC is between 4.90 and 5.20 volts. Once the system is running power monitoring
software will SHUT DOWN the board if VCC drifts outside the range of 4.85 to 5.20 volts.
Jumpers
The only jumper useable by customers is J3. It is labeled NOBOOT and is located near H3. If for
some reason the firmware becomes totally corrupted, and the system will not boot, use an
alligator clip or other suitable tool to short across the two contacts of J3. MAKE SURE YOU DO
NOT SHORT ANY OTHER CONTACTS! There are some in close proximity.
The system will not attempt to boot uCito. It will only load the boot monitor, which communicates
over the serial port at 57600 baud and with NO parity.
Modbus® EIA-485 Header
The K520 supports EIA-485 Modbus® serial communications. The standard configuration supports
half duplex Modbus®. There are also two additional lines which could be configured to support
full duplex Modbus® or two analog inputs for digital conversion. Please refer to the
Modbus® Schematic Page for more detail. Header HMB provides
the connections as shown in the following table.
| PIN | DESCRIPTION | PIN | DESCRIPTION |
| P1 | Shield | P4 | Logic Common |
| P2 | EIA-485 + | P5 | User Analog Input 1 |
| P3 | EIA-485 - | P6 | User Analog Input 2 |
The user analog inputs can support a resolution of 8 bits and a sample rate up to 100 per second.
The sample rate possible depends on how much computing the DSP is doing for peripheral functions
and the computing overhead for the user's application.
Host Serial Port Header
The K520 supports full bi-directional serial host communications. The host serial port header
H6 is a 10 Pin IDC connector. The connector pin-out is designed to directly connect to a
DB-9M IDC connector. DB-9M connector then has the same pin-out as a DB-9 from a PC.
Note: H3 is NOT a serial port header. Do not plug the host interface adapter cable into H3.
The serial port is OPTICALLY ISOLATED from the rest of the K520 PCB. A local DC/DC converter is
used to generate the +5V for the isolator and the serial port interface chip. The interface chip
uses charge-pump technology to generate the +/- 10V for RS-232 communications. The Isolated
Common on the cable headers is to connect the isolated common to the signal reference (ground)
of the PC.
Please refer to the tables below for the pin-outs of the header and cable. See the
Serial Interface Schematic Page for more details.
| PIN | DESCRIPTION | PIN | DESCRIPTION |
| 1 | N.C. | 6 | N/C |
| 2 | DSR (in) | 7 | DTR (out) |
| 3 | RXD (in) | 8 | N/C |
| 4 | RTS (out) | 9 | ISOLATED COMMON |
| 5 | TXD (out) | 10 | N/C |
| PIN | DESCRIPTION | PIN | DESCRIPTION |
| 1 | N.C. | 6 | DSR (in) |
| 2 | RXD (in) | 7 | RTS (out) |
| 3 | TXD (out) | 8 | CTS (in) |
| 4 | DTR (out) | 9 | N.C. |
| 5 | ISOLATED COMMON |
Host Serial Communication Cable
The Host port of the K520 is wired in the same way as a standard PC port. The Host port requires
a special cable to connect the K520 to a PC. The Host communication port is a male DB9 header.
To connect to a port on a PC, the required wiring is:
| MCU FUNCTION |
TYPE |
K520 DB9F |
HOST DB25F |
HOST DB9F |
| RXD | I | 2 | 2 | 3 |
| TXD | O | 3 | 3 | 2 |
| DTR | O | 4 | 6 | 6 |
| GND | P | 5 | 7 | 5 |
| DSR | I | 6 | 20 | 4 |
| RTS | O | 7 | 5 | 8 |
| CTS | I | 8 | 4 | 7 |
| SHIELD | CHASSIS* |
*The SHIELD must be grounded externally.
The K520 uses hardware handshaking (CTS/DTR) to control flow from a HOST computer into the controller. The Host must not transmit when CTS or DTR is inactive, otherwise characters may be lost or the internal buffer may overflow.
NOTE: To test the above wiring, use the COMT.UC file supplied by ExtraTech. This file
will test the communications cable including positive hand-shaking. Cables must be checked out
with a routine that forces handshaking, just checking communications in Machine Tools Suite does
not guarantee that all lines are correct.
Keypad Serial Port Header
Header H4 is used for the keypad serial port. See the Serial
Interface Schematic Page for more details.
| Device Function |
Type |
K520 H4 |
K520 DB15F |
KDM8S Header J1 |
| SHIELD | P | 1 | 1 | 1 |
| RXD | I | 3 | 2 | 3 (TXD) |
| TXD | O | 5 | 3 | 2 (RXD) |
| DTR | O | 7 | 4 | 4 (DSR) |
| DSR | I | 11 | 6 | 6 (DTR) |
| LogicCom | P | 2,4,9 | 5,9,10 | 5 |
| VCC (+5V) | P | 10,12 | 13,14 | 8 |
AMD Reprogramming Header H3
The Header H3 is used to reprogram the boot monitor of the main system flash memory. This
connection should not be used except by trained personnel.
Field Serviceable Components
To see component positions, see the Physical Layout page.
| Socket Location | IC Type | Description |
| U13,U46 | MAX202ECPE, ADM202EAN | EIA-232 Driver (serial port) |
| U21 | MAX3089CPD | MODBUS® Interface (optional) |
Modbus® is a registered trademark of MODICON