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Model PMDX-411

SmartBOB-USB-DB25   $119.00
(for use with Mach4)

click HERE to compare SmartBOB models



PMDX-411 SmartBOB-USB as delivered
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PMDX-411 SmartBOB-USB showing interior
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The PMDX-411 is a motion control pulse engine to allow CNC machines with parallel port style inputs to be connected to the Mach4 family of software using a USB port. 


Purchase as a bundle with a Mach4Hobby license and save
an additional $5 on our already discounted price for Mach4.

PMDX-411 SmartBOB-USB with Mach4 Logo


Features of the PMDX-411 Rev A

1) Motion controller inside the shell of a male DB-25 plug that connects directly to the female DB-25 on a PMDX-340, the Geckodrive G540, and many breakout boards including the PMDX-126. You can use a simple gender changer if you need to mate with a DB-25 male. You can also connect directly to stepper drivers and simple switches with just a wire harness.

2) The motion control pulse engine generates pulses independent of the host computer timing and provides real time control for smooth step pulse signals up to 100 KHz on 4 axes.

3) Simple USB connection to the host computer supports both CNC operation and firmware updates. 

4) Power is supplied via the USB connection so no power supply is needed.

5) The PMDX-411 provides equivalent signals to one parallel port including 8 step and direction signals, 5 input signals including one dedicated to emergency stop, and 4 output signals. 

6) The inputs are compatible with 5 volt or 3.3 volt logic signals. These inputs are also equipped with pull up resistors so that they can be used with directly connected mechanical switches or NPN sensors.

7) The PMDX-411 supports the PMDX-126 breakout board running in Expanded Input mode to allow 9 inputs including emergency stop from the PMDX-126.

8) The step and direction outputs are 5 volt logic signals with up to 24 mA of drive current available. In addition to interfacing to a breakout board, they can also directly drive the step and direction inputs of motor drivers.

9) The 4 control outputs are also 5 volt signals with up to 24 mA of drive current available. In addition to interfacing to a breakout board, these signals can also drive solid state relays.

10) All outputs are turned off in the event of loss of communication from the host, or if the emergency stop input is activated.

11) Two externally visible LEDs show the status of host connection and the SmartBOB-USB board.

12) The USB connection is provided by a 16" long cable with a USB style A male connector that can plug directly into a computer.

13) Using a directly attached pigtail cable avoids having a fragile mini-USB jack inside the PMDX-411 that can be damaged by pulling on the cable. 

14) Convenient thumb screws allow the PMDX-411 to be firmly attached to your breakout board or driver box.

15) The cable length can be extended to 15 feet using good quality USB A-to-A extension cables such as our PMDX-USB-AtoA-Extension.

PLEASE NOTE: The available step and direction signal pinouts work with most common breakout boards and with the PMDX-340 and Geckodrive G540, but they are not totally assignable at random. Please verify that your device is compatible before purchasing. Available configurations are Step on pins 2, 4, 6, 8 and Direction on pins 3, 5, 7, 9 <<OR>> Step on pins 3, 5, 7, 9 and Direction on pins 2, 4, 6, 8.

User's Manual Pending

Quick Start Guide here
(Revision 0.4, 6 May 2015, 81 KB)

Download Plug-In Setup files here

Instructions for getting Mach4 and your License File (bundle purchase only) 

The PMDX-411 is priced at $119.00

PMDX-411 >> SmartBOB-USB-DB25
Use PayPal shopping cart for USA delivery only,
click here for international orders.

PMDX-411-BUNDLE >> SmartBOB-USB-DB25 bundled with Mach4 Hobby

Software, coupon for license file, and documentation are delivered by e-mail and web download only. No physical disks or manuals are supplied.

To obtain your license file, please follow the instructions here:


Cables are sold separately, please click here to order the ones that you need.

Use PayPal shopping cart for USA delivery only.
Click here for international orders.


For International customers or for alternate payment options - click HERE