SD-800(DOCS) Optical Printer Control System SD-800(DOCS)
NAME
sd-800 - OPCS 8 channel "stepper distribution" (SD) card
DESCRIPTION
The OPCS "Stepper Distribution" card (SD-800) was designed to
simplify wiring between the computer step pulse generator card
(e.g. RTMC16, RTMC48, Kuper Industrial, A800..) and the stepper
motor driver modules (Centent, Gecko, LeadShine, etc) by breaking
out the DB-37 connector into separate RJ-45 patch cables, one per
stepper drive channel.
This board really has no active features on it, other than a fanout
to simplify wiring. Optional pullup resistor networks can be used
if the application requires open collector outputs from the card
to be pulled up to +5V for the idle state to prevent noise.
As of this writing, there is only one version of the board, REV 0,
which looks like this:
DB-37 PORT
(To RTMC or A800 cards)
____________________
__________|____________________|_________
| | | |
| |____________________| |
| |
| |
| |
| |
| ______________________________ |
| | | |
| | A B C D | |
| |______________________________| |
| | | |
| | E F G H | |
|____|______________________________|_____|
\____________________________/
Eight RJ-45
Connectors
(Two Tiers)
Typically the female DB-37 connector on the board is connected
to the DB-37 connector on the ISA stepper pulse generator card
plugged into the the DOS computer using 6' male/male cable.
And separate RJ-45 patch cables are wired to the A/B/C/D..
ports at the bottom of the board, which run out to the individual
stepper drives (Centent, Gecko, LeadShine, etc).
The DB-37 follows Kuper's pinout; see 'man kuper' for more info.
The RJ-45 pinout diagram is on the board, but is basically:
RJ-45 WIRE CENTENT GECKO LEADSHINE
PIN# SIGNAL COLOR (*) DRIVE DRIVE DRIVE
---- ---------- -------- ----------- ----------- ------------
1 GND - N/C N/C N/C
2 GND - N/C N/C N/C
_ 3 GND - N/C N/C N/C
DIR | 4 DIRECTION BLU DIRECTION (8) DIR DIR-(DIR)
|_ 5 +5V WHT/BLU +5 VOLTS DC (10) COMMON DIR+(5V-24V)
_ 6 GND - N/C N/C N/C
STP | 7 +5V WHT/BRN N/C N/C PUL+(5V-24V)
|_ 8 STEPS BRN STEP PULSE (9) STEP PUL-(PUL)
(*) Premade RJ-45 patch cables for cat5 and cat5e usually have
the standard wire colors shown above. For the signals used,
the wiring colors are the same for 568A and 568B.
Basically only 4 of the 8 wires are used. In some cases only 3 wires
are used (Centent & Gecko).
Please note these signals are DIRECTLY FROM THE COMPUTER MOTHERBOARD,
so be very careful with them. Do not let them short to chassis ground
on the printer, or to each other.
For N/C (X) wires, be sure to isolate them from each other to prevent
shorts. Either cut them to different lengths as shown below, and tape
or heat shrink them to protect them from each other:
Wires to
Drive Terminals
___________
/ \
|| || || ||
|| || || || Unused wires
|| || || || _________
|| || || || / \
...||.||.||.||.................
. || || || || .
. || || || || || .
. || || || || || .
. || || || || || || .
. || || || || || || . <-- heat shrink wrap
. || || || || || || || .
. || || || || || || || .
. || || || || || || || || .
. _||_||_||_||___||_||_||_||_ .
.| |.
.| |.
.|...........................|.
| |
| RJ-45 |
| CABLE |
| |
Ensure there's enough difference in the wire lengths so that
there's no way for their cut ends to touch each other, as the
conductors at the cuts are still live.
Or, cut the wires close to the cable shield, splay them apart,
and put a large blob of liquid electrical tape over them to
isolate them.
When wiring the Centent or Gecko's, be EXTRA careful with the
unused +5V signal wire (WHT/BRN). You don't want that shorting out
to ANYTHING, or the entire computer's 5V supply will shut down,
causing the machine to reboot (if you're lucky) or blow its internal
fuse or worse. So BE CAREFUL with that.
When wiring to the screw clamp terminals, I advise tining the wires
(if they're stranded) before inserting them, to prevent wire fraying
and shorts from stray pieces of stranded wire.
Use heat shrink to prevent wire fatigue at the screw terminal points,
and use nylon tie downs to also prevent wire motion at the screw
terminals.
AUTHOR
Greg Ercolano / Seriss Corporation 2021