
The AirTAC Airtac CMSJ Reed-type Sensor CMSJ-030 is a genuine CMS magnetic position switch. It senses the magnet ring in a pneumatic cylinder's piston and signals when the piston reaches that point, giving a 2-wire output on 5-240 V AC/DC with a 3 m flying lead. It only works on a cylinder that carries a piston magnet.
AirTAC's CMSJ-030 is a magnetic reed position switch that reports piston position on an AirTAC cylinder fitted with the magnet option. The reed element is a sealed mechanical contact, so the unit draws nothing from the supply and simply closes or opens the 2-wire loop. Because it is a reed type, it accepts 5-240 V AC or DC without polarity concerns and carries IP64 general protection on its 3 m flying lead.
That 3 m lead is the practical difference from the 020 version - extra reach to a junction box or terminal rail without splicing. One characteristic worth knowing: a reed contact can bounce and has a finite mechanical life, unlike a solid-state DMS, so for very high cycling duty an electronic switch may serve better. The J profile letter defines the groove fit on the cylinder; verify it against your cylinder model, since an unmatched profile will not seat in the tie-rod or band slot.
| Model | Airtac CMSJ Reed-type Sensor CMSJ-030 |
|---|---|
| Family | CMS — Reed switch cylinder sensor |
| Technology | Reed (magnetic contact) |
| Output | 2-wire |
| Outputs in this family | 2-wire contact |
| Lead / connector | 3 m flying lead |
| Supply voltage | 5-240 V AC/DC |
|---|---|
| Protection rating | IP64 |
| Version | Standard version |
| Profile letter | J (cylinder-groove fit) |
| Profiles in this family | E, G, H, J |
| Detects | Piston magnet ring inside the cylinder |
A reed contact switches a wide window, 5-240 V AC or DC, which is why it suits AC circuits and relay logic. IP64. The CMS range has no RW / IP68 option - that belongs to DMS and EMS. Switching distance, response time, current rating, voltage drop, LED behaviour, contact life, weight and dimensions are not published in our data set — ask us and we will confirm from the factory datasheet.
| CMS | Reed switch cylinder sensor — reed (magnetic contact). |
|---|---|
| J | Profile letter: the mounting / groove type that fits a particular cylinder body. This family offers E, G, H, J. It is a fit code, not a performance grade. |
| 030 | 3 m flying lead. 020 / 030 / 050 / 100 are 2 / 3 / 5 / 10 m flying leads; M08 and M12 are M8 / M12 connector versions. |
| (blank) | Standard version. On a CMS the suffix -H is the high-temperature version — do not confuse it with the H profile letter. |
We do not hold the full profile-to-cylinder-series table, so confirm the profile letter against your cylinder model before ordering — send us the cylinder part number and we will check the fit.
The split is electrical, not quality. Solid-state DMS and EMS are DC-only and suit modern PLC inputs; the reed-based CMS switches a much wider window, so it is the one for AC circuits, relay logic and older panels. The RW (IP68) option exists on DMS and EMS only.
| This switch | CMSJ · 2-wire · 5-240 V AC/DC |
|---|---|
| Consider DMS | the solid-state range with NPN / PNP 3-wire outputs (DC only) |
| Consider EMS | the mini 2-wire solid-state switch (DC only) |
| Mounting parts | F-MQ (round body), F-ACT (tie-rod) |
End-of-stroke sensing on the reject-gate cylinder of a carton packaging conveyor; the 3 m lead reaches a panel-mounted relay base without an extension.
Clamp confirmation on a fixture cylinder of a milling machine, wired in series with an existing 24 V DC interlock loop like a conventional limit switch.
Advance signal from the stopper cylinder on a pallet conveyor in a distribution centre, using the AC/DC contact across mixed legacy control voltages.
Choose the CMSJ-030 when you want a passive, polarity-free contact that drops into an existing AC or low-voltage DC circuit. It is a 2-wire series device, wired much like a mechanical limit switch, with small leakage current. If the run to your control cabinet is longer, the 5 m CMSJ-050 or an M8/M12 connector variant saves a splice; if the spot is hot, take the -H build instead. Confirm the J profile matches your cylinder's sensor groove, and order the cylinder with the -S magnet option - without the magnet the switch has nothing to read.
Quick checklist
Use the F-MQ bracket on round-body cylinders and F-ACT on tie-rod cylinders where there is no groove to seat the switch. Both are ordered separately from the switch. Switching distance and mounting dimensions come from the factory datasheet — ask us for the sheet that matches your cylinder.
Type: CMS magnetic reed switch with a mechanical 2-wire contact. Output: 2-wire, non-polar. Supply: 5-240 V AC or DC. Protection: IP64 general type. Wiring: 3 m flying lead. The contact acts like a passive switch in series with your load.
Only cylinders with the built-in magnet option can be detected, and the J profile must match that cylinder's sensor groove - the letter is a fit code, not a performance grade. Give us your cylinder series and we will confirm the right profile from the datasheet.
Genuine AirTAC parts produced by AirTAC factory.
Covers non-human-caused product damage.
Standard models are processed and dispatched in 3-5 business days.
Most inquiries answered within 7-8 hours.
Send us the quantity, your cylinder model (so we can confirm the profile fit) and the destination. We confirm price, availability and lead time — usually within 7-8 hours.