Selecting SENA Promi Bluetooth Adapters for Omron PLC Serial

1. Overview: Omron's Bluetooth Serial Strategy

Omron's SD1000-BT kit has been a long-standing option for engineers who need a wireless link between a programming laptop, an HMI, or a smart device and an Omron PLC serial port (RS-232C on CP1W-CIF01, CP1W-CIF11, CJ1W-SCU21, CJ2M-CIP11, etc.). The kit is sold through Omron's industrial automation channel at a list price around EUR 307 in the European catalog, and it is built around a Bluetooth-to-serial adapter originally developed by SENA Technologies, a Korean specialist in industrial Bluetooth and short-range RF modules. Omron's official position, as expressed by their EU support desk, is that the device is now sourced directly from SENA rather than from the older Promi-brand modules that Omron previously qualified.

For the end user the practical questions are:

• Is the Omron-branded unit a standard SENA module simply re-badged, or is the firmware/hardware customized?
• Can a generic SENA Promi-SD101 / SD102 / SD202 be ordered at a lower price and used as a drop-in replacement?
• What are the real differences between the SD1000 (powered) and SD200 (battery) variants?

This reference covers the SENA product family that intersects with Omron's PLC ecosystem, the configuration tools, the driver behavior on Windows, and the field-proven caveats that distinguish a bench-tested setup from a working production cell.

2. SENA Promi Product Family Architecture

The SENA Promi family is organized around a common Bluetooth 2.0+EDR/3.0 Class 1 radio (typical +18 dBm transmit, receiver sensitivity approximately -88 dBm) coupled with a Cortex-M-class microcontroller that runs a configuration command interpreter. The host interface varies by sub-model:

All Promi modules use the Bluetooth Serial Port Profile (SPP). On a Windows host they expose a virtual COM port through the Widcomm / Broadcom Bluetooth stack or through the Microsoft Bluetooth stack when paired with a generic SPP service UUID (0x1101). This is the layer that CX-Programmer, Sysmac Studio, and the OMRON connect mobile app all consume.

3. Omron SD1000-BT: Rebranded vs. Customized Hardware

From the discussion in the field, the only confirmed differences between the Omron SD1000-BT and a generic SENA Promi-SD1000 are:

1. Label and packaging: Omron applies its own part number, EAN, and a printed quick-start card. The plastic enclosure, PCB, and antenna are SENA OEM.
2. Default Bluetooth device name: Omron-branded units may boot with OMRON-SD1000 as the friendly name, while generic SENA units use Promi-SD1000-XXXX where XXXX is the last four hex digits of the BD_ADDR.
3. Default PIN/passkey: SENA ships with 0000 by default on most SKUs. Omron-branded units in some firmware revisions ship with 1234 for legacy compatibility with older Omron documentation.

None of those three differences affects protocol behavior. The SPP service UUID, the escape-sequence AT interpreter, the baud-rate auto-detect range, and the data path are identical. In other words: the Omron SD1000-BT is a re-branded, re-flashed SENA Promi-SD1000, not a custom hardware design. The Omron value-add is qualification, warranty, and a single part number on the bill of materials — not engineering differentiation.

4. Model Selection: SD1000 vs SD200

The two non-trivial decision axes are power source and operating mode.

4.1 Powered variants (SD101, SD102, SD1000)

These are intended for permanent installation. The radio stays on indefinitely, the SPP link re-establishes automatically on a known peer, and the host serial port is continuously bridged to the Bluetooth peer. Use them when:

• The PLC is inside a cabinet with a free 5 V or 12 V DC tap.
• The wireless link is the primary programming path (no USB or Ethernet available).
• You need a transparent RS-232 extension to a remote HMI or panel.

4.2 Battery variant (SD200 / SD202)

The SD200 carries an internal 3.7 V Li-ion cell charged through a mini-USB port. Typical continuous-on runtime is 8–12 hours at default TX power. Use it when:

• You roam between multiple machines with one laptop and want zero wiring.
• There is no clean DC tap near the PLC's serial port.
• You need a temporary link for commissioning and do not want to install DIN hardware.

The SD200 is a poor choice for permanent installation: the battery ages, and a discharged SD200 silently drops the SPP link. If you must use an SD200 permanently, plan a monthly charging cycle and verify with a watchdog on the application side (the Omron PLC host link protocol has no built-in keep-alive, but CX-Programmer's online monitor will time out at the configured Communications Timeout).

5. Interface Selection: RS-232, RS-422/485

The SENA Promi family is split between RS-232-only (SD series) and RS-422/485 (ESD series). Omron's PLC serial ports are RS-232 by default; CP1W-CIF11 and CJ1W-SCU41 add RS-422/485. If you need RS-422/485 over Bluetooth, you must use a Promi-ESD, not an SD.

For an NJ/NX controller the Promi path is largely historical. Modern Sysmac controllers expose EtherNet/IP and OPC UA; the Bluetooth-to-serial route is only used for legacy tool links, and a USB-serial adapter plus the SD101 is the more common bridge.

6. Driver and Pairing Configuration

On Windows 10/11 the Promi SPP service is bound to a virtual COM port through one of two stacks:

1. Microsoft Bluetooth stack (default on most clean Windows installs). The SPP service appears as Standard Serial over Bluetooth link; the COM number is assigned by Windows and is not always stable across reboots.
2. Broadcom / Widcomm stack (still bundled on some industrial laptops from Getac, Panasonic, Dell Rugged). Adds a Bluetooth Serial Port service and a configurable COM number that survives reboots.

6.1 Pairing sequence (Microsoft stack)

1. Open Settings → Bluetooth & devices and confirm Bluetooth is on.
2. Select Add device → Bluetooth. The Promi should appear as Promi-SD1000-XXXX (or OMRON-SD1000 on Omron units).
3. Enter the PIN: 0000 for generic SENA, 1234 for some Omron-branded units. Confirm.
4. Open More Bluetooth options → COM Ports. Note the assigned Outgoing COM number. This is the COM port you will enter in CX-Programmer or Sysmac Studio.

6.2 Pairing sequence (Broadcom / Widcomm)

1. Right-click the Bluetooth tray icon → Open Settings → Local Services.
2. Add a serial service: select Bluetooth Serial Port, choose a fixed COM number (e.g. COM7), mark Secure if you want authentication.
3. Right-click the Promi device → Pair. Confirm PIN.
4. The fixed COM number is the one to use in CX-Programmer.

7. Promi-SET Configuration Software Parameters

SENA's Promi-SET utility is the only supported tool for changing the adapter's behavior beyond the factory defaults. It communicates with the adapter over a temporary USB or RS-232 cable, and writes the configuration to non-volatile memory. Key parameters:

7.1 Mode 1 vs Mode 2 behavior

Mode 2 (default) makes the Promi a passive SPP slave: it accepts any incoming Bluetooth connection. This is the right choice for ad-hoc laptop links — you pair once, you connect when you need to.

Mode 1 makes the Promi a master that auto-connects to a specific peer BD_ADDR stored in its non-volatile memory. Use this for a permanent install: once the laptop is paired and trusted, the Promi will re-establish the SPP link within ~5 seconds of the laptop coming into range, with no user interaction. This is also the only mode that survives a power cycle cleanly in a 24/7 cell.

7.2 AT command line

Promi modules accept a small set of AT-style commands when the local serial port is in command mode (entered with the $$$ escape sequence). Useful for scripted commissioning:

$$$                       (enter command mode, response: CMD)
AT+BTINFO=<BD_ADDR>      (set target peer for Mode 1)
AT+BTPIN=1234             (change PIN)
AT+BTNAME=Line3-CP1L      (change device name)
AT+UART=115200,8N1        (set UART)
--END--                   (exit command mode)

Note that $$$ must be the only character sent in a 1-second guard window. CX-Programmer online traffic will not collide with command mode as long as the tool is in offline state.

8. Compatibility with Omron PLCs

The Promi SPP bridge is transparent at the byte level — it does not interpret the host-link or FINS protocol. The bridge will work with:

• CX-Programmer (versions 9.x and later) over Host Link on CP1, CJ1, CJ2 series.
• Sysmac Studio (versions 1.20 and later) over the same Host Link, when targeting a CP1 or CJ2 with a serial option board.
• OMRON connect mobile app on iOS and Android: the SPP bridge appears as a standard serial port, and the app binds to it through the OS Bluetooth settings. App-side pairing is documented on the OMRON connect iOS App Store page.
• NB / NS HMI series, when the HMI is configured for serial Host Link and the Promi is at the PLC end.

What the Promi does not do: it does not implement CIP, EtherNet/IP, or FINS over TCP. If your application uses those protocols, use a wired Ethernet or an Omron WE70 / WD210-series wireless Ethernet bridge instead.

9. Power, Range, and Environmental Specifications

In a typical 19-inch cabinet with the PLC, a Promi at the top of the cabinet, and a steel door closed, the effective range drops to 10–20 m. For shop-floor distances beyond that, consider an external antenna variant (some Promi SKUs offer an SMA connector; verify with the SENA datasheet) or step up to an industrial wireless Ethernet bridge.

10. Field Commissioning and Verification

A repeatable commissioning procedure prevents 80 % of the field headaches:

1. Power the Promi from a clean 5 V tap or USB. Measure the voltage at the Promi's terminal block under load; < 4.75 V causes intermittent resets.
2. Connect the DB-9 to the PLC's serial port. Use a known-good null-modem cable if the PLC is DCE and the Promi is wired as DTE (or vice versa). CP1W-CIF01 is DTE; most Promi RS-232 ports are also DTE — you need a null-modem or a straight-through if the SENA port is configured DCE (check the Promi-SET UART tab).
3. Pair the laptop on the appropriate Bluetooth stack. Write down the assigned COM number.
4. Set the host protocol in CX-Programmer: Host Link (SYSMAC WAY), COM number from step 3, baud rate matching the PLC's DIP switch (default 9600), unit number 0.
5. Go online. If online succeeds, the bridge is functional. If it fails with Timeout, the most common cause is mismatched RS-232 lines (TX/RX swap) or wrong DIP switch on the PLC option board.
6. Lock the link in Promi-SET: set Operation Mode 1 with the laptop BD_ADDR, set a unique device name, set a non-default PIN, and write to NV memory.
7. Document the COM number on a label affixed to the cabinet door. Future engineers will thank you.

10.1 Troubleshooting matrix

11. Sourcing and Pricing Considerations

The Omron SD1000-BT kit is typically listed at EUR 307 through Omron's EU catalog. The SENA Promi-SD1000 ships for roughly EUR 110–150 through SENA's authorized distributors, and the SENA Promi-SD101 (almost identical in functionality) is sometimes available for EUR 90–130 on the surplus market. The SENA Promi-SD200 with battery is usually EUR 180–220.

For a 5- or 10-unit rollout the savings are non-trivial. For a single service laptop used twice a year, the Omron-branded warranty and the single-part-number convenience may still be worth the premium. The technical risk of using a generic SENA unit is low because the Omron-branded and SENA-branded units are physically the same hardware.

12. Frequently Asked Questions