The MB2 breakout board from CNCRoom is a good alternative also.http://www.cncroom.com/break-out-board/smooth-stepper
MachBob2 (MB2) is designed for industrial application and specifically to work with the Ethernet
Smooth Stepper (ESS) which is an excellent motion control board designed to be used with Mach3
Here are some of the good features.
Utilizes all three ports from the ESS.
Accept frequency up to 4 MHz.
Differential line driver for motion signals enables longer wiring with more resistance to
interference when compared to TTL open end.
A single 24Vdc Power Supply is needed. There is a 5Vdc isolated and non‐isolated dc2dc
converter on board, thus saving installation space and wiring.
OSSD (Output Signal Switching Device) outputs and safety circuit are implemented when a
peripheral device such as a servo motor drive or a spindle VFD trigger an alarm condition, which
causes the Safety Circuit to disengage the OSSD output. This method is used in large CNC machines
to cut power from the drives.
LED status for all inputs and outputs including motion control signals. This makes it much
easier to diagnose and trouble shoot.
Polarity and over voltage protection (in conjunction with a fuse) for the 24Vdc power supply.
- An “AnaSpeed” circuit has been implemented. This circuit is totally isolated from the MB2 and forms
a part of the VFD inverter, acting as a digital VR. High voltage noise from the inverter
cannot cause interfere through this connection.
- A Charge‐Pump signal is provided. This helps the user to form a safety interlock condition among
controller and devices.
- 22 isolated input terminals, consisting of 17 terminals of NPN and 5 terminals of PNP type.
- 14 NPN isolated output terminals capable of sinking current up to 100mA for each channel and up to
500mA per group.
MB2v1.5, 2 onboard relays with both NO / NC contacts and “Off Delay Time”, which can be
used for “Z Drop Protection” application. (MB2v1.3 does not have this feature)