Industrial IO-Link master ifm model AL1591

Technical specifications

Application

hygienic systems; I/O modules for field applications

Loop-through function

voltage supply; fieldbus interface; IoT interface

Operating voltage [V]

20...28 DC; (US ; to PELV)

Current consumption [mA]

300...3900; (US)

Protection class

III

Additional voltage supply [V]

20...28 DC; (UA)

Max. current load total [A]

3.6

Current rating per port [A]

2

Total number of inputs and outputs

16; (configurable)

Number of inputs and outputs

Number of digital inputs: 12; Number of digital outputs: 12

Number of digital inputs

12; (IO-Link Port Class A: 4 x 2; IO-Link Port Class B: 4 x 1)

Switching level high [V]

11...28

Switching level low [V]

0...5

Number of digital outputs

12; (IO-Link Port Class A: 4 x 1; IO-Link Port Class B: 4 x 2)

Short-circuit proof

Yes

Max. current load per output [mA]

350

Parameter setting options

Node-RED

Operating system

Embedded Linux

Communication interface

Ethernet; IO-Link

Factory settings

IP address: 169.254.x.x; subnet mask: 255.255.0.0; gateway IP address: 0.0.0.0; MAC address: see type label

Transmission standard

100Base-TX

Transmission rate

100 MBit/s

Protocol

MQTT JSON; OPC UA

Note on interfaces

Secure protocol: HTTPS, MQTTS, TLS

Transmission type

COM1 (4,8 kBaud); COM2 (38,4 kBaud); COM3 (230,4 kBaud)

IO-Link revision

1.1

Number of ports class A

4

Number of ports class B

4

Ambient temperature [°C]

-25...60

Storage temperature [°C]

-25...85

Max. relative air humidity [%]

90

Protection rating

IP 65; IP 66; IP 67; IP 69K; (operation with stainless steel protective caps: IP 69K)

Protection rating (NEMA 250)

6P

Pollution degree

2

Chemical media

ISO 16750-5: HLP, CC, DB, DC, DD, CA; NEMA 250 5.13.1: AA

EMC

EN 61000-6-2; EN 61000-6-4

Shock resistance

DIN EN 60068-2-27

Vibration resistance

DIN EN 60068-2-64 2009-04; DIN EN 60068-2-6 2008-10

MTTF [years]

38

Weight [g]

649.55

Housing

rectangular

Type of mounting

backplane mounting

Dimensions [mm]

238 x 74.3 x 24

Materials

housing: PA grey; socket: stainless steel (316L/1.4404)

Sealing material

EPDM

Items supplied

Protective cap: 1 x M12, stainless steel, E12542

Remarks

For further information please see the operating instructions.

Pack quantity

1 pcs.

Connector

1 x M12; coding: L; Contacts: 5; Sealing: EPDM

Fieldbus protocol

EtherNet/IP or PROFINET; factory setting EtherNet/IP.

IoT protocol

Independent IoT interface: MQTT JSON and OPC UA; secure protocols HTTPS, MQTTS and TLS.

Manufacturer I/O scope

16 total configurable I/O; 12 digital inputs and 12 digital outputs are configuration capabilities, not 24 simultaneously available channels. Four Class A and four Class B ports. IP69K requires stainless steel protective caps.

Sensor supply US scope

20–28 V DC; 3.6 A total; 2 A per port. Digital output current limit is separately 350 mA per US output; do not equate output and port supply ratings.

Actuator supply UA scope

20–28 V DC; 4 A total and 4 A per port. Total limit still applies.

Connector topology review scope

Page 4: IO-Link connector header says Contacts 4 while Class B pin 5 is assigned UA minus; Ethernet header says 2 x M12 while XF1/XF2 and XI1/XI2 are listed. Connector topology and pin count require further verification.

Housing depth review scope

Drawing depth 40.9 mm and mechanical table 24 mm may refer to different envelopes; do not infer interchangeable housing depth.

Documents / datasheets

Source reviewed: 2026-10-24

Description

Industrial IO-Link master ifm part number AL1591; Operating voltage [V]: 20...28 DC; (US ; to PELV); Current consumption [mA]: 300...3900; (US); Additional voltage supply [V]: 20...28 DC; (UA). Technical specifications, condition and supply feasibility are checked before ordering.