1734-4IOL — POINT I/O 4-Port IO-Link Master Module

The 1734-4IOL is a 4-port IO-Link master module for the 1734 POINT I/O system. Each port connects to an IO-Link-capable sensor or actuator — proximity switches, photoelectric sensors, pressure transmitters, RFID readers, valve islands — and retrieves both process data and device parameter data over the same standard cable that would otherwise carry only a binary on/off signal. The module manages the IO-Link communication on all four ports simultaneously and presents the data to the controller over the POINT I/O backplane.

IO-Link is an IEC standard (IEC 61131-9) specifically designed to give standard IO-Link ports access to the intelligence already present inside modern sensors. A pressure sensor with IO-Link capability doesn't just output 1/0 — it outputs the actual pressure value, its switch point settings, its device health status, and its identification data. All of that travels over a standard unshielded 3-wire cable at up to 38.4 kbps. The 1734-4IOL is the gateway that connects that device intelligence to the POINT I/O node and, through it, to the controller program.

Specifications

Parameter	Value
Part Number	1734-4IOL
Platform	POINT I/O (1734)
IO-Link Ports	4 (independent)
IO-Link Specification	IEC 61131-9, IO-Link Rev 1.1
Port Type	Class A (standard)
Communication Speeds	COM1 (4.8 kbps), COM2 (38.4 kbps), COM3 (230.4 kbps)
Process Data per Port	Up to 32 bytes input + 32 bytes output
Power per Port	Up to 200 mA @ 24V DC (Port Power from module)
Standard I/O Mode	Yes (SIO mode — standard 24V DC digital I/O when no IO-Link device connected)
Cable Type	Standard 3-wire unshielded (M12 or 7/8-inch connectors)
Max Cable Length	20 m per port
Backplane Current (5V)	200 mA
Operating Temperature	−20°C to 55°C
Standards	IEC 61131-9, UL 508, CE

IO-Link in Plain Terms

Traditional discrete sensors connect to a digital input module and send a 1 or a 0 — the sensor is either tripped or it isn't. That's all the information the controller receives. If the sensor is a photoelectric that's detecting a part, all you know is "part present" or "part not present." You don't know the sensor's signal strength, whether the lens is dirty, whether it's about to fail, or what its detection distance is set to.

IO-Link changes this without requiring a new cable standard or a complex fieldbus infrastructure. The communication uses the same M12 3-wire cable as a conventional PNP sensor. At the device end, the sensor includes an IO-Link communication chip. At the master end, the 1734-4IOL generates the IO-Link clock signal that switches the port from standard digital I/O mode to IO-Link communication mode.

Once in IO-Link mode, the device sends cyclic process data (the measurement value or switch state, updated continuously) and responds to acyclic service data requests (parameter reads and writes, diagnostic queries). The master buffers the process data and passes it to the controller at the POINT I/O scan rate. Service data exchanges happen on demand through explicit messaging from the controller program or from an asset management tool.

Installation and Network Setup

The 1734-4IOL installs in a standard POINT I/O terminal base on a 1734 AENT or other adapter node. Each of the four ports connects to an IO-Link or standard 24V DC device via M12 cables. Configuration in Studio 5000 requires adding the 1734-4IOL to the POINT I/O node's I/O tree and then configuring each port — device type, expected process data format, and any parameter download that should occur automatically when a device is connected.

Port configuration includes the IO-Link revision and communication speed. Most modern IO-Link sensors run at COM2 (38.4 kbps) or COM3 (230.4 kbps) — check the device's IODD file (IO-Link Device Description) for the correct speed setting.
The IODD file for each connected device defines the process data format and parameter structure. Import the IODD into the engineering tool (Logix Designer or an IO-Link-capable configuration tool) to get proper tag mapping and parameter descriptions.
Ports not connected to IO-Link devices operate in SIO (Standard I/O) mode automatically — they function as standard 24V DC digital inputs or outputs, compatible with conventional non-IO-Link sensors.
Device replacement: when a faulty IO-Link sensor is replaced with the same model, the master can automatically download stored parameter sets to the new device. This "auto-device replacement" feature means setpoints, switch points, and device configuration are restored without manual reconfiguration — a significant time-saver for field replacements.

FAQ

Q: Does IO-Link require special cables or connectors?

No — it uses standard 3-wire unshielded cable with M12 connectors, the same type used for conventional PNP sensors. No special shielding or cable type is required for runs up to 20 m.

Q: Can non-IO-Link standard sensors be connected to the 1734-4IOL?

Yes. Each port operates in SIO (Standard I/O) mode when a non-IO-Link device is connected. In SIO mode, the port behaves as a standard 24V DC digital input or output — the IO-Link capabilities simply aren't used for that port.

Q: Can the controller program write parameters to connected IO-Link devices — for example, changing a sensor's switch point remotely?

Yes. Acyclic service data communication (parameter read/write) is available through explicit MSG instructions from the controller program. Switch points, output logic, measurement range, and other device parameters can be written remotely without physically accessing the sensor.

Q: How does IO-Link process data arrive in the controller program?

Process data from each port maps to input/output tags in the controller's I/O image. The data structure depends on the connected device — a pressure sensor returns a 16-bit integer representing pressure; a valve island returns individual bit outputs. The IODD file defines the data format; the engineering tool maps it to named tags.

Q: What adapters are compatible with the 1734-4IOL?

All standard 1734 POINT I/O adapters — EtherNet/IP (1734-AENT), DeviceNet (1734-ADN), ControlNet, and others. The IO-Link master module communicates via the POINT I/O backplane regardless of which network adapter is at the node head.

1734-4IOL AB Point I/O 4Channel IO-Link Master Module New 17344IOL