We provide a custom compatible solution for the CMH58M-00002 encoder, focused on systems where low-resolution multiturn SSI feedback must remain stable in a compact hollow-shaft installation with M12 wiring, RS422 transmission, and locked preset behavior.
Model reading from the document:
- CMH58M-00002 = absolute rotary encoder
- 64 steps per revolution
- 128 revolutions
- SSI interface
- Binary code
- RS422 output level
- 11–27 VDC supply
- 12H7 hollow shaft
- 8-pin M12 radial connector on housing
- IP54 protection
- 0–60 °C operating temperature
Typical production lead time: 15 working days.
This model should not be treated like a high-resolution SSI encoder. Its system value is compact hollow-shaft absolute feedback, not fine interpolation. The first weak point is usually shaft clamping, moment-support positioning, SSI clock stability, M12 shield quality, or parity handling.
Where the System Fails First
The document defines the SSI format as 18 bit with even parity. That is a hard integration point. If the controller expects the wrong SSI word length or ignores parity, the encoder may look connected but return unusable position data.
Typical failure points:
- Wrong SSI format setting → invalid position decoding
- Poor M12 shield contact → unstable RS422 data
- Loose 12H7 hollow shaft fit → position drift
- Wrong moment-support pin/groove position → housing stress
- Preset input locked → field preset cannot be used
- Mixing programming RS485 lines with SSI lines → commissioning fault
The pinout is simple: power, ground, SSI Clock+/Clock-, SSI Data+/Data-, and serial programming RS485 pair. There is no direction input or preset input available in the field wiring structure shown on the 8-pin M12 connector. That matches the document note that the preset input is locked.
Mechanical and Signal Boundary
The drawing shows a compact hollow-shaft encoder with 12H7 hollow shaft, front-side clamping ring, and moment-support pin/groove. The mechanical risk is not high shaft load; it is small installation error. If the hollow shaft is not clamped cleanly or the support pin is forced, the housing will follow shaft vibration and the SSI value will appear unstable.
Mechanically, the document lists 6000 rpm maximum speed, 39 × 10⁹ revolutions bearing life, maximum angular acceleration 10⁵ rad/s², and IP54 protection. IP54 is not a washdown protection level. If this encoder is used in coolant, oil spray, or heavy dust, the connector and hollow-shaft area normally become the first reliability problem.
Installation Notes
- Keep the model format as CMH58M-00002
- Configure SSI as 18 bit with even parity
- Keep SSI Clock+ / Clock- as a clean differential pair
- Keep SSI Data+ / Data- as a clean RS422 pair
- Do not assume field preset is available; the document states preset input is locked
- Check 12H7 hollow shaft fit and clamping ring before replacing the encoder
- Do not force the moment-support pin/groove into alignment
- De-energize the system before wiring or connector work
Key Data
- Model: CMH58M-00002
- Type: Absolute rotary encoder
- Interface: SSI
- Code: Binary
- Resolution: 64 steps / revolution
- Multiturn range: 128 revolutions
- SSI format: 18 bit with even parity
- Supply voltage: 11–27 VDC
- Output level: RS422
- Shaft: 12H7 hollow shaft
- Connector: 8-pin M12
- Connector position: Radial on housing
- Protection: IP54
- Operating temperature: 0–60 °C
- Options: front-side clamping ring, short version, moment support pin/groove, programmable
- Pinout: ST3542
- Drawing: 04-CMH58M-M0002
