A custom compatible replacement for BMMH 58S1G24C12/13P25 can be supplied by EncoderWorks with the main check placed on Gray-code SSI cable pairing, IP65 sealing, and Ø12 mm blind hollow-shaft fit. This model should not be treated as a through-hollow-shaft encoder. The key mechanical point is that the bore is a blind hollow shaft: the machine shaft enters the encoder to a defined depth, but it does not pass fully through the encoder body.
The BMMH 58S1G24C12/13P25 is a magnetic SSI multiturn absolute encoder configuration with 12-bit singleturn resolution and 13-bit multiturn range. The 24C element indicates a 10–30 VDC SSI version, while G indicates Gray code. The P25 ending should be handled as IP65 protection, Ø12 mm blind hollow shaft, and radial cable execution. For replacement selection, this suffix must be confirmed against the original label and mounting drawing before production.
The first failure boundary is SSI cable pairing. Data+ / Data- and Clock+ / Clock- must remain differential pairs through the full cable route. If the cable is extended through a terminal strip, junction box, or cabinet entry without preserving pair structure and shielding, the controller may receive shifted SSI words, intermittent position values, or speed-dependent read errors.
This replacement fails when SSI communication is active, but the PLC reads unstable or incorrect multiturn values because Clock/Data pair assignment, cable shielding, termination, or Gray-code interpretation does not match the original installation. The encoder can be functional while the signal chain is wrong.
The second boundary is blind hollow-shaft mounting. A blind hollow shaft is not a through bore. It must match the shaft diameter, insertion depth, clamping position, and torque-support arrangement. If the installer assumes a through-hollow design, the shaft may bottom out, sit too shallow, preload the bearing, or leave the clamping zone in the wrong position.
Zero setting must also be controlled. The zero input can set the electrical reference within the encoder resolution. If this line is triggered during wiring, tied to the wrong level, or confused with an unused conductor, the machine can receive a stable but offset absolute position.
The replacement decision should first confirm P25 suffix execution, Ø12 mm blind hollow-shaft fit, insertion depth, IP65 requirement, radial cable assignment, 10–30 VDC SSI supply, 12-bit singleturn and 13-bit multiturn mapping, Gray code setting, Clock/Data differential pair wiring, data termination, zero input behavior, shield grounding, torque support, and shaft seating. EncoderWorks treats BMMH 58S1G24C12/13P25 as an industrial encoder custom compatible solution where SSI cable integrity and blind hollow-shaft mechanics decide field reliability.
Typical production lead time: 15 working days.
Key Data
| Item | Data |
|---|---|
| Model | BMMH 58S1G24C12/13P25 |
| Encoder type | Multiturn absolute encoder |
| Interface | SSI |
| Sensor technology | Magnetic |
| Resolution | 12-bit singleturn + 13-bit multiturn |
| Code | Gray |
| Supply voltage | 10–30 VDC |
| Signal standard | SSI clock input, RS422 data output |
| Shaft type | Blind hollow shaft, not through hollow |
| Shaft size | Ø12 mm |
| Connection | Radial cable |
| Protection class | IP65 |
| Control input | Zero setting input |
| Main engineering anchor | Gray SSI cable and blind hollow shaft |
| Main failure boundary | Wrong SSI pair mapping, zero-set error, blind-shaft seating error, shield fault |
