Mesa 5i25 User manual

5I25
ANYTHING I/O
MANUAL
Version 1.10

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iii
Table of Contents
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
HARDWARE CONFIGURATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
GENERAL .................................................... 2
BREAKOUT POWER OPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
5V I/O TOLERANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
PRECONFIG PULL-UP ENABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
PCI BUS ISOLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
CONNECTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
CONNECTOR LOCATIONS AND DEFAULT JUMPER POSITIONS . . . . . . . . 4
5I25 I/O CONNECTOR PIN-OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
JTAG CONNECTOR PIN-OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
FPGA ........................................................ 8
FPGA PINOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
PCI ACCESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
CONFIGURATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
EEPROM LAYOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
BITFILE FORMAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
NMFLASH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
MESAFLASH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
SPI INTERFACE DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
FREE EEPROM SPACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
FALLBACK INDICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
FAILURE TO CONFIGURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
CLOCK SIGNALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
LEDS ....................................................... 15
PULLUP RESISTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
I/O LEVELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
STARTUP I/O VOLTAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
INTERFACE CABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
BREAKOUT POWER OPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
PLUG AND GO KITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

iv
Table of Contents
SUPPLIED CONFIGURATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
HOSTMOT2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7I76X2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7I76_7I74 .................................................... 17
G540X2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7I77X2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7I77_7I76 .................................................... 17
7I77_7I74 .................................................... 18
7I74X2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7I78X2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
PROB_RFX2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
PIN FILES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
REFERENCE INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5I25 1
GENERAL
DESCRIPTION
The MESA 5I25 SuperPort is a low cost, general purpose programmable I/O card
for the PCI bus. The 5I25 is a low profile PCI card and is available with standard or low
profile brackets. The 5I25 uses standard parallel port pinouts and connectors for
compatibilitywithmostparallelportinterfacedmotioncontrol/CNCbreakoutcards,allowing
a motion control performance boost while retaining a reliable real time PCI interface.
The 5I25 is a universal PCI card so will work in 5V and 3.3V systems. The 5I25
provides 34 I/O bits (17 per connector). All I/O bits have bus switches that provide 5V
tolerance and also have the benefit of disconnecting all I/O pins when the host CPU is off,
preventing damage to the 5I25 if power is supplied to I/O pins when the host is powered
down. All I/O pins have pull-up resistors, so have a defined state at power up. Unlike the
parallelportthatthe5I25replaces,eachI/Obithasindividuallyprogrammabledirectionand
function.
A power source option allows the 5I25 to supply 5V power to breakout boards if
desired. This 5V power is protected by a per connector PTC.
Configurations are provided for hardware step generation (to MHz rates), encoder
counting, PWM, digital I/O, analog I/O, and Smart Serial remote I/O.Configurations are
available that are compatible with common breakout cards and multi axis step drives like
the Probotix-RF and the Gecko G540.
There are currently five 5I25 compatible breakout cards available from Mesa, the
7I74 through 7I78.
The7I74isaeightchannelRS-422interfacenormallyusedwithMesa’sSmartSerial
remote I/O expansion cards. The 7I75 is a simple breakout/protection card that gives direct
bidirectional access to all FPGA pins. The 7I76 is a step/dir oriented breakout with 5 axis
of buffered step/dir outputs, one spindle encoder input, one isolated 0-10V analog spindle
speed plus isolated direction and enable outputs, one RS-422 expansion port, 32 isolated
5-32V inputs and 16 isolated 5-32V 300 mA outputs. The 7I77 is a analog servo interface
with 6 encoder inputs, 6 analog +-10V outputs, one RS-422 expansion port, 32 isolated
5-32Vinputs,and16isolated5-32V300mA outputs.The5I25 supportstwobreakoutcards
so for example a 10 Axis step/dir configuration or 12 axis analog servo configuration is
possible with a single 5I25 and two Mesa breakout cards. The 7I78 is a simple 4 axis
bufferedstep/dirinterfacewithisolatedanalogspindlecontrolandspindleencoderinterface
plus one RS-422 port for I/O expansion.

5I25 2
HARDWARE CONFIGURATION
GENERAL
Hardwaresetupjumperpositionsassumethatthe5I25cardisorientedinanupright
position, that is, with the PCI connector towards the person doing the configuration.
BREAKOUT POWER OPTION
The5I25 has the option to supply 5V power from the host computer to the breakout
board. This option is used by all Mesa breakout boards to simplify wiring. The option uses
4 parallel cable signals that are normally used as grounds for supplying 5V to the remote
breakout board (DB25 pins 22,23,24 and 25). These pins are AC bypassed on both the
5I25 and Mesa breakout cards so do not compromise AC signal integrity.
The 5V power option is individually selectable for the two I/O connectors. The
breakout 5V power is protected by per connector PTC devices so will not cause damage
to the 5I25 or system if accidentally shorted. This option should only be enabled for Mesa
breakout boards or boards specifically wired to accept 5V power on DB25 pins 22 through
25. When the option is disabled DB25 pins 22 through 25 are grounded
W1 (P2 POWER ) W2 (P3 POWER)
UP UP BREAKOUT POWER ENABLED
DOWN, DOWN BREAKOUT POWER DISABLED (DEFAULT)
5V I/O TOLERANCE
The FPGA used on the 5I25 has a 4V absolute maximum input voltage
specification. To allowinterfacing with 5V inputs, the 5I25 has bus switches on all I/O pins.
The bus switches work by turning off when the input voltage exceeds a preset threshold.
The 5V I/O tolerance option is the default and should normally be left enabled.
For high speed applications where only 3.3V maximum signals are present and
overshoot clamping is desired, the 5V I/O tolerance option can be disabled. W3 controls
the 5V I/O tolerance option. When W3 is on the default UP position, 5V tolerance mode
is enabled. When W3 is in the DOWN position, 5V tolerance mode is disabled. Note that
W3 controls 5V tolerance on both P2 and P3 I/O connectors.
W3 also selects the pull-up resistor voltage, When 5V I/O tolerance mode is
selected, the I/O pull-up resistors are powered from 5V. When 5V I/O tolerance mode is
disabled, the I/O pull-up resistors are powered with 3.3V.

5I25 3
HARDWARE CONFIGURATION
PRECONFIG PULLUP ENABLE
The Xilinx FPGA on the 5I25 has the option of having weak pull-ups on all I/O pins
at power-up or reset. The default is to enable the pull-ups. To enable the built-in pull-ups,
(the default condition) jumper W4 should be placed in the UP position. To disable the
internal pull-ups, W4 should be in the DOWN position.
PCI BUS ISOLATION
The 5I25 uses bus switches to provide 5V tolerance on the PCI bus. These bus
switches can be turned off to disconnect the FPGA from the PCI bus. This is valuable
when debugging FPGA PCI firmware. W5 controls the PCI bus isolate function. For
normal operation W5 must be in the UP position. To disconnect the FPGA from the BUS,
move W5 to the DOWN position.

5I25 4
CONNECTORS
CONNECTOR LOCATIONS AND DEFAULT JUMPER POSITIONS

5I25 5
CONNECTORS
I/O CONNECTORS
The5I25has2I/Oconnectors,theprimaryDB25FconnectorP3andthesecondary
26 pin header connector P2, please see the 5I25IO.PIN file on the 5I25 distribution disk.
5I25 IO connector pinouts are as follows:
P3 BACK PANEL DB25F CONNECTOR PINOUT
DB25 PIN FUNCTION DB25 PIN FUNCTION
1 IO0 14 IO1
2 IO2 15 IO3
3 IO4 16 IO5
4 IO6 17 IO7
5 IO8 18 GND
6 IO9 19 GND
7 IO10 20 GND
8 IO11 21 GND
9 IO12 22 GND or 5V
10 IO13 23 GND or 5V
11 IO14 24 GND or 5V
12 IO15 25 GND or 5V
13 IO16

5I25 6
CONNECTORS
I/O CONNECTORS
P2 INTERNAL HDR26 CONNECTOR PINOUT
HDR PIN FUNCTION HDR PIN FUNCTION
1 IO17 2 IO18
3 IO19 4 IO20
5 IO21 6 IO22
7 IO23 8 IO24
9 IO25 10 GND
11 IO26 12 GND
13 IO27 14 GND
15 IO28 16 GND
17 IO29 18 GND or 5V
19 IO30 20 GND or 5V
21 IO31 22 GND or 5V
23 IO32 24 GND or 5V
25 IO33 26 GND or 5V
Note: 26 pin header P2 will match standard parallel port pin-out if terminated with
flat cable 26 pin receptacle/DB25F cable with pin1s connected (and header pin 26 left
open)
A cable/bracket hardware kit is available from MESA for the second port.

5I25 7
CONNECTORS
JTAG CONNECTOR PINOUT
P1 is a JTAG programming connector. This is normally used onlyfor debugging or
if the EEPROM configuration has beencorrupted. In case of corrupted EEPROM contents
the EEPROM can be re-programmed using Xilinx’s Impact tool. For reprogramming, the
card can be powered in a standard PCI slot or if desired, 3.3V power can be applied via
the JTAG connector.
P1 JTAG CONNECTOR PINOUT
PIN FUNCTION
1 TMS
2 TDI
3 TDO
4 TCK
5 GND
6 +3.3V

5I25 8
OPERATION
FPGA
The 5I25 use a Xilinx Spartan6 ~400k gate FPGA in a 144 pin QFP package:
XC6SLX9-PQ144.
FPGA PINOUT
The local bus and I/O interface FPGA pinouts are described in the 6i25.ucf file in
the /configs/hostmot2/source directory of the 5i25.zip file.
PCI ACCESS
The 5I25 normally uses 5I25 specific HostMot2 firmware which currently has a
simple target only PCI core with a single Base Address Register (BAR 0). Card specific
PCI identifiers are as follows:
VENDOR ID 0X2718
DEVICE ID 0x5125
SUBSYSTEM VENDOR ID 0x2718
SUBSYSTEM DEVICE ID 0x5125
The single base address register (BAR0) maps a 64K Byte region of non-cacheble 32 bit
wide memory.
.

5I25 9
OPERATION
CONFIGURATION
The 5I25 is configured at power up by a SPI EEPROM. This EEPROM is an 8M bit
chip that has space for two configuration files. Since all PCI bus logic on the 5I25 is in the
FPGA, a problem with configuration means that PCI access will not be possible. This
condition is only fixable by reprogramming the EEPROM via the JTAG connector P1,
which is awkward and slow at best. For this reason the 5I25 EEPROM normally contains
two configuration file images, A primary user image and a fallback image. If the primary
user configuration is corrupted, the FPGA will load the fallback configuration so the
EEPROM image can be repaired without having to resort to JTAG programming.
EEPROM LAYOUT
TheEEPROMusedonthe5I25forconfigurationstorageistheM25P80orM25P16.
The M25P80 is a 8 M bit (1 M byte) EEPROM with 16x 64K byte sectors. The M25P16 is
a 16 Mbit (2 M byte) EEPROM with 32x 64K byte sectors Configuration files are stored on
sector boundaries to allow individual configuration file erasing and updating. M25P80
EEPROM sector layout is as follows:
0x00000 BOOT BLOCK
0x10000 FALLBACK CONFIGURATION BLOCK 0
0x20000 FALLBACK CONFIGURATION BLOCK 1
0x30000 FALLBACK CONFIGURATION BLOCK 2
0x40000 FALLBACK CONFIGURATION BLOCK 3
0x50000 FALLBACK CONFIGURATION BLOCK 4
0x60000 FALLBACK CONFIGURATION BLOCK 5
0x70000 RESERVED
0x80000 USER CONFIGURATION BLOCK 0
0x90000 USER CONFIGURATION BLOCK 1
0xA0000 USER CONFIGURATION BLOCK 2
0xB0000 USER CONFIGURATION BLOCK 3
0xC0000 USER CONFIGURATION BLOCK 4
0xD0000 USER CONFIGURATION BLOCK 5
0xE0000 UNUSED/FREE
0xF0000 UNUSED/FREE

5I25 10
OPERATION
EEPROM LAYOUT
The first half of M25P16 sector layout is as follows:
0x00000 BOOT BLOCK
0x10000 FALLBACK CONFIGURATION BLOCK 0
0x20000 FALLBACK CONFIGURATION BLOCK 1
0x30000 FALLBACK CONFIGURATION BLOCK 2
0x40000 FALLBACK CONFIGURATION BLOCK 3
0x50000 FALLBACK CONFIGURATION BLOCK 4
0x60000 FALLBACK CONFIGURATION BLOCK 5
0x70000 RESERVED
0x80000 UNUSED/FREE
0x90000 UNUSED/FREE
0xA0000 UNUSED/FREE
0xB0000 UNUSED/FREE
0xC0000 UNUSED/FREE
0xD0000 UNUSED/FREE
0xE0000 UNUSED/FREE
0xF0000 UNUSED/FREE

5I25 11
OPERATION
EEPROM LAYOUT
The second half of M25P16 sector layout is as follows:
0x100000 USER CONFIGURATION BLOCK 0
0x110000 USER CONFIGURATION BLOCK 1
0x120000 USER CONFIGURATION BLOCK 2
0x130000 USER CONFIGURATION BLOCK 3
0x140000 USER CONFIGURATION BLOCK 4
0x150000 USER CONFIGURATION BLOCK 5
0x160000 UNUSED/FREE
0x170000 UNUSED/FREE
0x180000 UNUSED/FREE
0x190000 UNUSED/FREE
0x1A0000 UNUSED/FREE
0x1B0000 UNUSED/FREE
0x1C0000 UNUSED/FREE
0x1D0000 UNUSED/FREE
0x1E0000 UNUSED/FREE
0x1F0000 UNUSED/FREE

5I25 12
OPERATION
BITFILE FORMAT
The configuration utilities expects standard FPGA bitfiles without any multiboot
features enabled. If multiboot FPGA files are loaded they will likely cause a configuration
failure. In addition for fallback to work, the -g next_config_register_write:disable, -g
reset_on_error:enable and -g CRC:enable bitgen options must be set.
WARNING: Never write a bitfile that is not designed for a 5I25 into the 5I25s
EEPROM as this will likely "brick" the 5i25 card and require he card to be returned
to Mesa for repair.
NMFLASH
The DOS utility program NMFLASH is provided to write configuration files to the
5I25 EEPROM under DOS. NMFLASH depends on a simple SPI interface built into both
the standard user FPGA bitfiles and the fallback bitfile.
NMFLASH FPGAFILE.BIT
Writes a standard bitfile FPGAFILE.BIT to the user area of the EEPROM
NMFLASH FPGAFILE.BIT V
Verifies the user EEPROM configuration against the bit file FPGAFILE.BIT
NMFLASH FALLBACK.BIT FallBack
WritesthefallbackEEPROMconfigurationtothefallbackareaoftheEEPROM.Inaddition
if the bootblock is not present in block 0 of the EEPROM, it re-writes the bootblock.
MESAFLASH
Linux and Windows utility programs mesaflash and mesaflash.exe are provided to
write configuration files to the 5I25 EEPROM. These files depend on a simple SPI
interface built into both the standard user FPGA bitfiles and the fallback bitfile.
If mesaflash is run with a B help command line it will print usage information.
mesaflash --device 5I25 --write FPGAFILE.BIT
Writes a standard bitfile FPGAFILE.BIT to the user area of the EEPROM.
mesaflash --device 5I25 --verify FPGAFILE.BIT
Verifies the user EEPROM configuration against the bit file FPGAFILE.BIT.
mesaflash --device 5I25 --fallback --write FALLBACK.BIT
Writes a fallback file to the fallback area of the EEPROM

5I25 13
OPERATION
SPI INTERFACE DESCRIPTION
This is the register level description of the simple SPI interface to the 5I25's
configuration EEPROM. This hardware is built into all Mesa 5I25 configurations. This
information is only needed if you are writing your own programming utility.
DATA REGISTER at offset 0x74 from 5I25 base address
D7 D6 D5 D4 D3 D2 D1 D0
R/W R/W R/W R/W R/W R/W R/W R/W
CONTROL REGISTER at offset 0x70 from 5I25 base address
X X X X X DAV BUSY CS
X X X X X R/O R/O R/W

5I25 14
OPERATION
SPI INTERFACE DESCRIPTION
The SPI interface is very minimal, just enough hardware to avoid slow bit banging
of the SPI data when reading or writing the configuration EEPROM. Operation is as
follows: To transfer SPI data, CS is asserted low and an outgoing command/data byte is
written to the data register. This write to the data register causes the SPI interface to clear
its DAV bit, shift out its outgoing data byte, and shift in its incoming data. This shifting is
done at a fixed PCI Clock/6 rate or about 5.5 MHz. When the byte data transfer is done,
The DAV bit is set in the control register. Host software can poll this bit to determine when
the transfer is done. When the transfer is done the incoming data from the EEPROM can
be read in the data register, and the next byte sent out.
Note that CS operation is entirely controlled by the host, that is for example with a
5bytecommand sequence, the host must assert CS low, transfer 5bytes with 5write/read
commands to the data register with per byte DAV bit polling and finally assert CS high
when done.
FREE EEPROM SPACE
Three 64K byte blocks of EEPROM space are free when both user and fallback
configurations are installed. It is suggested that only the last two blocks, 0xE0000 and
0xF0000 in the user area, be used for FPGA application EEPROM storage.
FALLBACK INDICATION
Mesa’s suppliedfallback configurations blink theredINIT LED on the topright hand
side of the card if the primary configuration fails and the fallback configuration loaded
successfully. If this happens it means the user configuration is corrupted or not a proper
configuration for the5I25s FPGA. This can be fixed by running the configuration utility and
re-writing the user configuration.
FAILURE TO CONFIGURE
The 5I25 should configure its FPGA within a fraction of a second of power
application. If the FPGA card fails to configure, both red LEDs on the right hand side of
the card will remain illuminated after power up. If this happens the 5I25s EEPROM must
be re-programmed via the JTAG connector.
CLOCK SIGNALS
The 5I25 has two FPGA clock signals. One is the PCI clock and the other is a 50
MHz crystal oscillatoron the5I25 card. Both clocks a can be multiplied and divided by the
FPGAs clock generator block to generate a wide range of internal clock signals. Note that
the PCI bus clock is often not known to a high degree of accuracy so for accurate timing
applications, the on card 50 MHz oscillator should be used.

5I25 15
OPERATION
LEDS
The 5I25 has 2 FPGA driven user LEDs (User 0 and User 1 = Green), and 2 status
LEDs (red). The user LEDs can be used for any purpose, and can be helpful as a simple
debugging feature. A low output signal from the FPGA lights the LED. See the 5I25IO.PIN
file for FPGA pin locations of the LED signals. The status LEDs reflect the state of the
FPGA’s DONE, and /INIT pins. The /DONE LED lights until the FPGA is configured at
power-up. The /INIT LED lights when the power on reset is asserted, when there has been
a CRC error during configuration. When using Mesas configurations, the /INIT LED blinks
when the fallback configuration has been loaded.
PULLUP RESISTORS
All I/O pins are provided with pull-up resistors to allow connection to open drain,
open collector, or OPTO devices. These resistors have a value of 3.3K so have a
maximum pull-up current of 1.5 mA (5V pull-up) or 1 mA (3.3V pull-up).
IO LEVELS
The Xilinx FPGAs used on the 5I25 have programmable I/O levels for interfacing
withdifferentlogicfamilies.The5I25doesnotsupportuseoftheI/Ostandardsthatrequire
input reference voltages. All standard Mesa configurations use LVTTL levels.
Note that even though the 5I25 can tolerate 5V signal inputs, its outputs will not
swing to 5V. The outputs are push pull CMOS that will drive to the output supply rail of
3.3V. This is sufficient for TTL compatibility but may cause problems with some types of
loads. For example when driving an LED that has its anode connected to 5V, in such
devices as OPTO isolators and I/O module rack SSRs, the 3.3V high level may not
completely turn the LED off. To avoid this problem, either drive loads that are ground
referred, Use 3.3V as the VCC for VCC referred loads, or use open drain mode.
STARTUP I/O VOLTAGE
After power-up or system reset and before the the FPGA is configured, the pull-up
resistors will pull all I/O signals to a high level. If the FPGA is used for motion control or
controlling devices that could present a hazard when enabled, external circuitryshould be
designed so that this initial state results in a safe condition.

5I25 16
OPERATION
INTERFACE CABLES
Mesa daughtercards use a male to male DB25 cable to interface to the 5I25. For
noise immunity and signal fidelity it is suggested that only IEEE-1284 rated cables be
used. IEEE-1284 rated cables have a twisted pair shield wire for each signal wire and an
overall shield terminated in the metal connector shell. This results in much better
performancethanflatorNON-IEEE-1284parallelportcablesForshortconnectionsofless
than 3 feet, flat cables can be used. No other type of cable should be used.
MesacansupplyIEEE-1284cablestestedwiththe5I25/daughtercardcombination
in 6 and 10 foot lengths.
BREAKOUT POWER OPTION
When used with Mesa breakout/daughter cards, the 5I25 can supply up to 1A of 5V
power to each of the daughter cards. This option is disabled by default to avoid possible
damage to standard breakout boards, so must be specifically enabled for Mesa
daughtercards. If you use this option you must verify that the interface cable does not tie
the eight parallel port ground wires together as some cheap printer cables do. Mesa
supplied IEEE-1284 cables are the best option for Mesa daughter cards and are
guaranteed to work with the power option. Flat cable will work as well but have poorer
noise immunity and signal fidelity.
PLUG AND GO KITS
Motioncontrolkitswithpre-programmed5I25,interfacecable,anddaughtercard(s)
are available to simplify system integration.