Reading AS-i Data via IE/AS-i Link PN IO Gateway in PROFINET

System Architecture Overview

The IE/AS-i Link PN IO (catalog number 6GK1411-2AB10, firmware-compatible successor 6GK1411-2AB20) terminates an AS-Interface (AS-i) network segment on the field side and presents it as a PROFINET IO device on the controller side. In the configuration discussed here, the AS-i segment hosts a SIRIUS 3RA6 compact starter 3RA6120-1CB34 fitted with the AS-i connection module 3RA6970-3A. The PROFINET side connects to the integrated PROFINET interface (X150 P1) of a SIMATIC S7-300 CPU 319-3 PN/DP acting as the PROFINET IO controller.

From the controller's perspective, the gateway is a single PROFINET IO device with a GSD-defined slot structure. Each AS-i slave assigned to the gateway occupies one slot, and the I/O bytes of that AS-i slave become the cyclic I/O of the corresponding PROFINET submodule. The CPU maps the slots into its process-image I/O area, and the STEP 7 program reads and writes the data using standard load/transfer instructions or the standard distributed-I/O blocks.

The data path is three layers deep:

1. AS-i slave on the compact starter. The 3RA6970-3A exchanges cyclic I/O with the gateway acting as AS-i master. Typical process data is 4-bit DI / 4-bit DO for status and control of the starter; the exact profile is selected during commissioning with the AS-i addressing unit.
2. IE/AS-i Link PN IO. The gateway exposes each AS-i slave as a PROFINET submodule on a slot and additionally offers acyclic manufacturer-specific records for AS-i diagnostics. The gateway is a standard PROFINET IO device; it does not require any proprietary block library to exchange data.
3. S7-300 CPU 319-3 PN/DP. The PROFINET IO controller reads and writes the submodules cyclically via the I/O area, and reads diagnostic data acyclically with SFB52 "RDREC" / SFB53 "WRREC" (STEP 7 V5.x) or the equivalent RDREC / WRREC instructions in TIA Portal.

Hardware Components and Catalog Numbers

Refer to the IE/AS-i Link PN IO device manual (PDF) for terminal assignments, diagnostic-LED meaning, and the supported AS-i master specifications. The PI (PROFIBUS & PROFINET International) product-finder entry for the gateway family is published at PROFIBUS product finder - IE/PB Link PN IO for the cross-reference, while the AS-i-specific ordering data and GSD file are in the Siemens Industry Online Support entry 22712154.

Prerequisites and Software Tools

Obtain the GSD file and the matching firmware/HSP for the IE/AS-i Link PN IO from the Siemens support entry for catalog number 6GK1411-2AB10. For TIA Portal, the device is included in the device catalog of the SIMATIC PC station profile after the GSD is installed; for STEP 7 V5.x, install the GSD via HW Config, menu "Options > Install GSD File".

AS-i Network Setup and Slave Addressing

Each AS-i slave has a unique address from 1 to 31 on a single AS-i network. The compact-starter module 3RA6970-3A uses a single address; the address is set with the AS-i addressing unit over the addressing socket on the front of the module, or through the IE/AS-i Link PN IO if the master supports automatic addressing (the 6GK1411-2AB10 supports automatic addressing of single slaves).

Repeat the addressing step for every AS-i slave on the network. Duplicate addresses cause the gateway to flag "AS-i config error" and refuse cyclic exchange with the affected slave; the LED on the slave module will not illuminate and the master's "SLAVE" LED for that address will blink red.

GSD File Installation

The IE/AS-i Link PN IO is a GSD-based PROFINET IO device, not a Siemens catalog device. The GSDML file (GSDML-V*-Siemens-IEASi_LINK_PN_IO-*.xml) is published on the Siemens Industry Online Support entry for the catalog number. Install it once per engineering station; subsequent project work does not require reinstallation.

1. Download the GSDML and any accompanying icon files to a local folder.
2. Start STEP 7 V5.x HW Config or TIA Portal.
3. For STEP 7 V5.x: menu Options > Install GSD File... > browse to the folder > select the GSDML > click Install.
4. For TIA Portal: menu Options > Manage general station description files (GSD) > browse to the folder > select the GSDML > Install.
5. Restart the engineering tool if the device does not appear in the catalog.

STEP 7 V5.x Device Configuration

Open the S7 project containing the CPU 319-3 PN/DP and double-click the PROFINET IO subnet of the CPU to open HW Config. Drag the IE/AS-i Link PN IO from the catalog to the PROFINET line; assign a unique device name (for example ie-asilink-01) and a unique IP address in the same subnet as the CPU's PROFINET interface.

1. Open HW Config, navigate to the CPU's PROFINET interface (X150 P1).
2. From the catalog PROFINET IO > Gateway > Siemens AG > IE/AS-i Link PN IO, drag the device onto the PROFINET line. The device appears with a slot 0 (DAP).
3. Right-click the device > Properties > General > set Device Name = ie-asilink-01 and IP Address = a free address in the controller's subnet.
4. Open Slot 1 of the gateway; insert the submodule AS-i Slave 1 (corresponding to AS-i slave address 1). Insert one submodule per AS-i slave address used.
5. For each AS-i slave submodule, right-click and open Properties > Addresses to set the start address of the I area (inputs from slave) and Q area (outputs to slave) within the CPU's process image. A typical AS-i 4-bit DI / 4-bit DO slave maps to 1 byte of I and 1 byte of Q; the gateway may pad the byte to a word. Avoid address collisions with other IO devices in the same project.
6. Save and compile the hardware configuration. Download the HW Config to the CPU. Use the "Accessible Nodes" function in HW Config to confirm the gateway comes online with the configured device name.

TIA Portal Device Configuration

The TIA Portal places the IE/AS-i Link PN IO under the device catalog at Other field devices > PROFINET IO > Gateway > Siemens AG > IE/AS-i Link PN IO after the GSD is installed. The configuration steps mirror the STEP 7 V5.x flow with these TIA-specific differences:

• The device view replaces HW Config. The PROFINET line is the connection between the CPU's PROFINET interface port and the gateway's port 1.
• The "Inspector" window on the gateway carries the Gateway > Network gateway as PROFINET IO proxy option (documented in the TIA Portal communication manual; the same option exists for the IE/PB Link context). Keep this option at its default unless the gateway must proxy non-PROFINET slaves to a different controller, in which case it acts as a PROFINET IO proxy.
• Submodule insertion: drag AS-i Slave n from the catalog into slot n of the device. Set the I/O addresses in the Inspector's "I/O addresses" tab.

The TIA Portal communication manual describes the proxy option in detail: Connect the DP slave via the IE/PB Link to a PROFINET IO system. The same "Network gateway as PROFINET IO proxy" option is available for the IE/AS-i Link PN IO and must remain at its default for direct PROFINET IO exchange.

Reading AS-i Process Data in the S7 Program

Once the gateway is in cyclic exchange with the CPU, the I/O bytes of the AS-i slaves are updated in the CPU's process image each PROFINET cycle. The STEP 7 program reads and writes the bytes directly without any proprietary block library.

Example: a 3RA6970-3A on AS-i address 1, configured at PROFINET I/O start address 10 (input byte) and 10 (output byte):

// STL (STEP 7 V5.x)
// Read AS-i input byte for slave 1
L     IB    10          // load input byte for AS-i slave 1
T     MB    100         // store in a flag byte for the program

// Bit-level evaluation of typical 3RA6 status signals
A     M100.0            // bit 0 = "starter on" feedback
=     DB20.DBX   0.0
A     M100.1            // bit 1 = "ready to start" feedback
=     DB20.DBX   0.1
A     M100.2            // bit 2 = "group fault"
=     DB20.DBX   0.2

For an OB1 cyclic read, the input byte is already part of the process image; for a time-critical read that must not wait for the OB1 update, use direct peripheral access:

// Direct peripheral read (bypasses process image, always current)
L     PIB   10          // load peripheral input byte
T     MB   100

Writing AS-i Process Data from the S7 Program

To control the compact starter through the AS-i module, the program writes the output bits in the process image. The PROFINET cycle delivers the bits to the gateway, which then updates the corresponding AS-i slave's DO bits. The 3RA6970-3A maps DO0 to the starter on/off control; the remaining DOs are unused or reserved by the slave profile.

// STL (STEP 7 V5.x)
// Set DO0 of AS-i slave 1 to start the motor
SET
S     M      110.0
// Reset DO0 to stop
CLR
=     M      110.0

// Transfer the flag byte to the output image
L     MB    110
T     QB    10

Acyclic Diagnostic Data Records (RDREC / WRREC)

The IE/AS-i Link PN IO exposes manufacturer-specific acyclic records that contain the AS-i slave list (LDS), the AS-i parameter echo, the configuration data, and the per-slave diagnostic buffer. The PROFINET IO controller reads these records with SFB52 "RDREC" (STEP 7 V5.x) or the RDREC instruction in TIA Portal. The exact record indices and lengths are defined in chapter 7 of the IE/AS-i Link PN IO device manual (PDF); the index values are also discoverable through the gateway's Web server under Diagnostics > Records.

Example STL for reading the AS-i slave list:

// Call SFB52 "RDREC" to read a record from the gateway
CALL  SFB52,  DB52
       REQ    := TRUE
       ID     := W#16#0100  // diagnostic address of the gateway slot 0
       INDEX  := 16#0010    // AS-i slave list, see IE/AS-i Link manual
       MLEN   := 200        // maximum record length
       VALID   := M200.0
       BUSY    := M200.1
       ERROR   := M200.2
       STATUS  := MW202
       LEN     := MW204
       RECORD  := P#DB100.DBX 0.0 BYTE 200

The returned buffer is interpreted using the structure documented in the IE/AS-i Link manual. For a quick health check, the first 4 bytes report the LDS bitmap (bit n = address n+1); a set bit indicates an active slave, a cleared bit indicates a missing slave.

For cyclic supervision of the AS-i segment, schedule the record read in OB1 (or in a slower OB35) and compare the LDS bitmap to the expected bitmap. A difference indicates a slave that has gone offline (cable break, address conflict, peripheral fault) and triggers a controller-side alarm.

Verification and Online Diagnostics

Run the following checks after the hardware configuration is downloaded to the CPU and the gateway is in cyclic exchange:

The gateway's Web server (default URL https://<ip>/, port 443) provides a maintenance page with the AS-i slave list, the LDS bitmap, the configuration data, the firmware version, and the PROFINET device name. Use the Web server during commissioning to confirm that the slaves are learned and the configuration matches the project.

Troubleshooting Matrix

Frequently Asked Questions