SD-1600 - 16 Channel DB37 "Stepper Distribution" Board

The SD-1600 breaks out the steps/direction signals for the DB-37 connector on Kuper Control's RTMC16, RTMC48 or Kuper Industrial boards
into separate RJ-45 connectors. This allows simple cat5 or cat6 patch cables to be used connect between these cards and the stepper motor drive modules.

Description

The SD-1600 board simplifies wiring of the DB37 connector provided by Kuper RTMC16 / RTMC48 and "Kuper Industrial" stepper motor "pulse generator" cards to the separate stepper motor drives. Each motor channel's step/direction pairs are combined onto separate RJ-45 connectors, so RJ-45 patch cables can be used to distribute the step/direction signals to each motor's drive.

RJ-45 cabling makes it easy to swap or reassign motors to different channels, and to modularize each channel for maintenance.

Currently there's only one revision of this board, REV-0.

SD-1600 Circuit Layout

The circuit board's layout was designed with Sprint6 Layout, which is commercial circuit board design software that's about $50 for a license. The Sprint6 project file for REV-0 is opcs-sd1600-REV-0.lay6. The Gebers are also provided in this opcs-sd1600-REV-0.zip zip file. The gerber files can be run off at most PCB printers, such as PCBWAY or JLCPCB.
Note: the "lay6" file and Sprint 6 softare are only needed to make edits (changes/customizations) to the board design. To just print boards without making modifications, skip all that and just use the above .zip file, which is all that's needed to print new boards as PCB's.

What follows are images of the circuit layout layers as they appear in Sprint6 Layout and/or a Geber viewer (such as the open source tool 'gerbv'), along with board mounting dimensions.

SD-1600 top and bottom layers (click for full sized image)
SD-1600 top copper layer	SD-1600 bot copper layer
SD-1600 photo top	SD-1600 photo bottom

SD-1600 Board Schematic

Sheet 1 of 1 (click for full sized image)

Installation and Configuration

When mounting the SD-1600, size #6 screws can be used. Use all 4 mounting holes, and use rubber or nylon standoffs to keep the back of the board from touching metal surfaces.

Use cable strain relief when possible for the DB-37 cable, to prevent tugs on cabling from stressing the DB37 connector on the SD-1600 card.

When wiring the RJ-45 cables to the stepper drives, follow the wiring diagram in the above schematic.

The SD-1600 has only one configurable option: the 4 resistor networks, RN1 thru RN4, which should be configured as follows:

• They should NOT be installed if the pulse generator outputs are TTL/CMOS level.


• They should be installed if the pulse generator outputs are open collector.

When 2K resistor networks are installed, they pull up the steps/direction outputs to +5, which for open collector outputs can decrease noise pickup when these signals are floating. Noise can cause motors to creep, or run erratically and loose position. Example: moving only channel B in reverse may cause neighboring channels A or C to creep or run improperly, or the moving channel B may not run correctly and loose position.

When you're experiencing noise problems during testing, install the four SD-1600's 2K pullup resistors in RN1 thru RN4. If noise problems persist, use a scope to check the step/direction signals at the motor drives. You should see the "steps" signal to normally reside at +5v, and fall to ground during stepping. The "direction" signal should either be +5v or GND during motor running, and not some value between.