Supported Optical and Magnetic DRO Scales

Support optical and magnetic DRO scales

TouchDRO adapters for optical and magnetic scales support DRO scales and rotary encoders that output 5V quadrature signal. This includes the vast majority of modern optical, magnetic, and inductive scales.

Purchasing New Scales

The vast majority of modern DRO scales use TTL (single ended signal) or RS-422 (differential signal) standard. This includes virtually 100% of the Chinese scales, and many current scale models from the legacy Western DRO brands like Acu-Rite, Newall, Magnescale, Heidenhein, etc. One notable exception are Mitutoyo scales, that use a proprietary serial protocol across the board. See the "Supported Scale Brands" section below for more information.

Many high-end DRO manufacturers produce scales that can be purchased with TTL/RS-422, analog sine/cosine output, or a proprietary data transfer scheme. When purchasing new DRO scales from Acu-Rite, Newall, Sony, etc., look for models that advertise TTL or RS-422 output with 0V/+5V power supply. Fortunately, the documentation for brand-name scales can usually be readily available online or can be requested by contacting the manufacturer.

Although virtually all Chinese DRO scales are compatible with TouchDRO, getting accurate documentation for some no-name scales can be a challenge. In many cases, you can reverse-engineer the pinout following the instructions in the How to Find Glass DRO Scale Pin Functions. To avoid the hassle, it's best to purchase your scales from one of the established Chinese brands. You can find more information on the Recommended DRO Scales

Using Existing Scales

DRO scales have been produced for at least the last 50 years or more, and there is a bewildering number of models on the used market. If you are considering upgrading your existing DRO display to TouchDRO, you will first need to figure out what protocol your scales use. Unfortunately, it's impossible to determine the communication protocol just from the scale brand and/or connector type. In most cases, you will need to find a datasheet or the user manual for your scales that contain the pinout diagram, pin descriptions or states that the scales output TTL signal. If the reference literature doesn't explicitly state that the scales provide TTL or RS-422 output, see if the pinout diagram includes the following pin names:


If the scale pinout includes lines marked: 5V (or Vcc), 0V (or Ground), A and B, the scale is compatible with TouchDRO. The scale might have lines marked R/Z, A', B', and R'/Z'. Those lines are supported but not necessary.
This includes:

Not Compatible

This includes:

Supported Scale Brands


Acu-Rite SENC 50 and SENC 150 TTL DRO Scales
Acu-Rite SENC 50 and SENC 150 TTL DRO Scales

Acu-Rite is a well known digital readout manufacturer that has been on the marker for several decades. Their newer SENC "digital" scales, such as SENC 50, SENC 125, and SENC 150 use TTL or RS-422 standard and are fully compatible with TouchDRO Adapters. The TDA-4xx adapter can be ordered with DB-9 connectors pre-configured for Acu-Rite SENC scales.
Older Acu-Rite "Mini-Scale" scales with round "PT06A-10-6P" connector output TTL signal and are compatible, but the plug needs to be replaced with a DB9 male connector.


Newall MHG-TT Microsyn scales are compatible with TouchDRO.
Newall MHG-TT Microsyn scales are compatible with TouchDRO.

Newall is another well known DRO brand that produces excellent specialty scales. Their main specialty are high-precision inductive scales. Many of their older scales used analog output, but the new Microsyn and Spherosyn scales include "***-TT" models that output TTL or RS-422 signal. This includes: MHG-TT, DSG-TT, DMG-TT, and MAG-TS.

Note that Newall sells their scales with pre-installed DB9 connectors for use with their own DRO units, and without connectors for use with competitive DROs. Before connecting Newall scales to TouchDRO, please ensure that the wire colors match the expected pinout.


Electronica/EMS Magna S1 and Magna Slim magnetic DRO scales
Electronica/EMS Magna S1 and Magna Slim magnetic DRO scales

Electronica Mechatronics Systems (EMS) is an Indian company that among other things produces several models of affordable magnetic DRO scales. This includes Magna Slim, Magna S1,S2 and MG232 Magna scales. Additionally, Precision Matthews MagExact DRO scales are re-branded EMS scales and use the same pinout. Most EMS scales on the market use RS-422 output and are compatible with TouchDRO, but the company offers models that output analog sine/cosine signal.

Ditron, Esson, Sino, Aikron

Ditron and Easson optical and magnetic scales.
Ditron and Easson optical and magnetic scales.

Ditron, along with Easson and Sino were the first Chinese DRO scale manufacturers to offer affordable optical DRO scales. Their scales are generally of very good quality, on par with comparable optical scales sold by the legacy DRO brands. Aikron is a relatively new company, but their scales appear to be of similar good quality. All four brands use compatible pinouts.
Additionally, many online store brands, such as Vevor, M-DRO, etc. use this pinout for their scales.

Easson has gone out of business a few years ago after their owner passed away, and new Easson scales are no longer sold. The situation with the Sino brand is somewhat unclear. "Sino" was a trademark owned by Guangzhou Lok SHUN CNC Equipment Ltd. As of mid-2020, Sino is a separate company that was established by one of the original Sino distributors, and the scales appear to be rebranded Ditron scales. Furthermore, some TouchDRO customers reported purchasing Sino-labeled scales from unknown seller that were of very poor quality.

Generic Chinese Scales

Generic Chinese DRO scales.
Generic Chinese DRO scales.

There are dozens, if not hundreds, of Chinese suppliers selling DRO scales under various names. This includes online marketplace brands like ToAuto, who sell rebranded scales from one of the mainstream manufacturers, to small "mom-and-pop" shops that sell factory rejects or overruns.

These scales are compatible with TouchDRO. Most generic Chinese scales use one of the three pinout "standards" listed in the table below.

  1 2 3 4 5 6 7 8 9
Ditron-compatible A' 0V B' Shield R'/Z' A +5V B R/Z
ToAuto, Jing, and others. 5V 0V A B