Configuring AS-i Master 3RK7137-6SA00-0BC1 in ET 200SP TIA Portal

Configuring AS-i Master 3RK7137-6SA00-0BC1 in SIMATIC ET 200SP with TIA Portal

This technical reference describes how to integrate the AS-i Master 3RK7137-6SA00-0BC1 into a SIMATIC ET 200SP station headed by a CPU 1510SP-1 PN, how to bring GEA process-valve slaves online without GSD files, and how to scale to dense installations of 48 slaves per network using dual-master topologies. The article follows official Siemens engineering guidance for the AS-Interface Safety Engineering Manual collection and the SIMATIC ET 200SP AS-i Master manual.

1. AS-i Network Architecture in ET 200SP

An AS-i network always comprises three logical elements: the master, an AS-i power supply unit (AS-i PSU), and the slaves. The master is the only bus arbiter; slaves have no bus-access intelligence of their own. Per the official Siemens Safety Engineering with AS-Interface manual, "a master module collects the process images of all connected AS-i slaves and exchanges them cyclically with the higher-level controller" — see Creating an AS-Interface network.

1.1 Topology Rules

• AS-i is a single-master system; the 3RK7137-6SA00-0BC1 is the only master allowed per yellow segment.
• Cable type: 2 x 1.5 mm² mechanically keyed yellow profile cable (piercing technology).
• Maximum cable length: 100 m per segment without repeater; up to 300 m with two repeaters.
• Cycle time: 5 ms for 31 standard slaves, 10 ms for 62 extended slaves.
• AS-i supply voltage: 30 V DC (29.5 V to 31.6 V) from a dedicated AS-i PSU such as 3RX9501-0BA00.

1.2 Logical Channel Model (A and B)

AS-i Version 3 introduced extended addressing. Each base address 1-31 may host two logical sub-addresses: A and B. This doubles the maximum slave count per master from 31 to 62.

2. Hardware Components Required

2.1 Head Station and Interface Module

• CPU 1510SP-1 PN (6ES7510-1SJ01-0AB0 or higher MLFB): SIMATIC ET 200SP CPU with PROFINET interface. Functions as PROFINET IO controller and ET 200SP head.
• AS-i Master 3RK7137-6SA00-0BC1: single-master AS-i V3.0 interface module for ET 200SP, occupies one slot in the BaseUnit.
• BaseUnit BU20-A5 (6ES7193-6BP20-0BA0 or -0DA0 depending on feed) for the AS-i Master slot.

2.2 AS-i Power Supply Unit

The AS-i Master 3RK7137-6SA00-0BC1 does not generate the 30 V DC AS-i supply. You must install a separate AS-i PSU such as 3RX9501-0BA00 or 3RX9503-0BA00. Wire the PSU in parallel with the yellow cable; the master itself taps both data and power from the same two conductors.

2.3 AS-i Slaves (GEA Process Valves)

For process-valve applications the GEA ASi Valve module exposes a standard AS-i slave profile:

• 2 DI: feedback bits (open / closed position indicators)
• 1 DQ: command bit (open or close coil drive)
• Total 48 slaves in the project, each typically on its own pneumatic actuator node.

3. AS-i Master 3RK7137-6SA00-0BC1 Technical Data

Excerpted from the official AS-i Master SIMATIC ET 200SP manual (PDF):

4. TIA Portal Hardware Configuration

4.1 Adding the AS-i Master to the Project

1. Open the device view of the CPU 1510SP-1 PN.
2. Insert a new slot; the AS-i Master 3RK7137-6SA00-0BC1 must be ordered from the catalog under AS-Interface > AS-i Master > SIMATIC ET 200SP.
3. Assign a BaseUnit BU20-A5 to the slot. Choose the feed-in variant if the module is the first on the segment.
4. Confirm the device name and PROFINET device number; the master is a PROFINET device sub-module of the ET 200SP station and inherits the IP configuration from the head.

4.2 Slot and Module Properties

In the inspector window you can edit the following parameters:

5. AS-i Slave Configuration Without GSD Files

AS-i slaves are not engineered via PROFINET GSD files. The master learns the slave catalog at runtime using the AS-i "scan slaves" procedure. The standard says "you do not need to project the AS-i slaves into HW config".

5.1 Scan Procedure

1. Compile the station and download hardware configuration to the CPU.
2. Open the AS-i Master's online diagnostics in TIA Portal (Online & diagnostics > AS-Interface).
3. Click "Scan AS-i slaves". The master enters learn mode and detects all physically connected slaves within ~5 s.
4. Detected slaves appear in a list with their I/O configuration (input bits, output bits, I/O code, ID code, profile).
5. Click "Store slave configuration" to write the learned configuration to non-volatile memory on the master.

5.2 Manual Address Assignment

Slaves are auto-numbered during scan, but in dense installations you typically want a deterministic address layout. Use either:

• AS-i addressing device (e.g. 3RK1904-2AB02) to set addresses before power-on, or
• Online "Change slave address" function in TIA Portal to overwrite the auto-assigned address.

5.3 Why No GSD Files Are Needed

PROFINET GSD files describe PROFINET devices. AS-i slaves are not PROFINET devices; they are AS-i devices. The only PROFINET-aware element on the bus is the AS-i Master 3RK7137-6SA00-0BC1. The master exposes the AS-i process image to PROFINET as a single sub-module with 16 bytes of input and 16 bytes of output, regardless of how many slaves are connected. Therefore:

• No GSD import is required for the GEA valve slaves.
• No I&M data is loaded per valve.
• No port interconnectors are needed.
• The PLC program accesses slaves via the master's process image using a fixed slot offset (see Section 7).

6. Multi-Master Strategy for 48 Slaves

If you have 48 physical slaves and they are all A-only or A/B mixed, you have two architectural options:

6.1 Option A — Single Master with Extended Addressing

If all 48 slaves support A/B sub-addressing and the valve profile permits both sub-addresses per node, you can run 48 slaves on one AS-i Master. The maximum theoretical limit is 62 (31A + 31B). In this case:

• Configure master in V3.0 mode.
• Each base address hosts two valves: e.g. 1A and 1B, 2A and 2B, etc.
• Cycle time: 10 ms.
• Total AS-i I/O: up to 248 DI + 248 DQ.

6.2 Option B — Dual Master (Recommended for Mixed Populations)

If the valve slaves are A-only, or if you want to separate process zones for safety / maintenance reasons, install two AS-i Master 3RK7137-6SA00-0BC1 modules in the same ET 200SP station:

• Master 1 manages 24 valves (addresses 1-24, A-channel).
• Master 2 manages 24 valves (addresses 1-24, A-channel of a separate yellow segment).
• Each master requires its own AS-i PSU (or one PSU feeding two segments via decoupling).

7. PLC Program Access to AS-i Process Image

7.1 Input Image Mapping

The AS-i Master exchanges 16 bytes of input data with the CPU via PROFINET. For each AS-i slave address n (1 to 31), 4 input bits are mapped:

Byte 0..3 = Inputs of slaves 1..4 (4 bits each, packed)
Byte 4..7 = Inputs of slaves 5..8
...
Byte 28..31 = Inputs of slaves 29..31 + reserved

Concretely, slave 1 input bit 0 = %I0.0, slave 1 input bit 3 = %I0.3, slave 2 input bit 0 = %I0.4, etc.

7.2 Output Image Mapping

Same scheme, output direction:

%Q0.0  = Slave 1, output bit 0
%Q0.1  = Slave 1, output bit 1
%Q0.2  = Slave 1, output bit 2
%Q0.3  = Slave 1, output bit 3
%Q0.4  = Slave 2, output bit 0
...

7.3 STL Example: Reading Valve Feedback

// GEA valve at AS-i slave address 12
// Bit 0 = open feedback, Bit 1 = closed feedback, Bit 2 = warning
// Output bit 0 = open command

      L     %I1.4       // Slave 12, bit 0 (open feedback)
      T     "DB_Valve".Feedback_Open_S12

      L     %I1.5       // Slave 12, bit 1 (closed feedback)
      T     "DB_Valve".Feedback_Closed_S12

      U     "DB_Valve".Cmd_Open_S12
      =     %Q1.4       // Slave 12, output bit 0 (open command)

7.4 Symbolic Tag Names with Standard Tags

For better readability, enable the "Standard tags" option in the master's properties. TIA Portal then creates a pre-mapped symbol table:

AS_i_Outputs   BOOL[4]  starting at QB0
AS_i_Inputs    BOOL[4]  starting at IB0
AS_i_Diag      WORD     at IW32

8. Firmware, Redundancy, and PROFINET System Redundancy R1

Current firmware of the 3RK7137-6SA00-0BC1 (≥ V2.0) supports operation under PROFINET System Redundancy R1. This requires:

• ET 200SP station head: IM 155-6 PN R1 (6ES7155-6AU30-0CN0 or higher) instead of the standard IM 155-6 PN.
• Two PROFINET controllers (H-system) configured with redundancy role "R1 device" for the station.
• CPU firmware compatible with the redundancy role (CPU 1510SP-1 PN ≥ V2.8).

When R1 is active, the AS-i Master survives a controller failover without dropping its 48 valves. State of the AS-i process image is preserved in the master's local memory and resynchronized on PROFINET reconnect.

9. AS-i Cabling and Power Supply Wiring

9.1 Wiring Rules

• Wire the AS-i PSU's two output terminals (ASI+ and ASI-) directly to the yellow profile cable.
• The master's BaseUnit spring terminals tap ASI+/ASI- internally from the backplane.
• Do not place a fuse in series with ASI+ — the PSU already limits current.
• Terminate the cable ends with the AS-i terminating piece (e.g. 3RX9801-0AA00) if reflections are observed on long runs.
• Maintain > 20 mm separation from VFD power cables.

9.2 Voltage Drop Calculation

For a 100 m loop carrying 24 valves @ 50 mA each plus 200 mA master draw:

Total_current = 24 * 0.05 + 0.2 = 1.4 A
Cable_resistance = 2 * 100 m * 0.0133 ohm/m = 2.66 ohm
Voltage_drop = 1.4 * 2.66 = 3.72 V

If 30 V is supplied and drop is 3.7 V, slave end sees 26.3 V — below the 29.5 V lower limit. Solutions: thicker cable, shorter loop, or a second AS-i PSU mid-cable.

10. Diagnostics and Error Codes

10.1 LED States on the 3RK7137-6SA00-0BC1

10.2 Common Error Codes (per AS-i V3.0 specification)

10.3 Online Diagnostics in TIA Portal

1. Right-click the AS-i Master in the device view.
2. Select Online & diagnostics.
3. Open the AS-Interface tab. The "Configured slaves" and "Detected slaves" tables are shown side-by-side.
4. For each slave with a fault, click the row to read the diagnostic buffer.

11. Commissioning Checklist

11.1 Pre-Power Checks

• [ ] AS-i PSU output voltage measured at end of cable: ≥ 29.5 V DC.
• [ ] Each valve slave address set to expected value with the addressing device.
• [ ] Yellow cable routed clear of VFD cables and welding circuits.
• [ ] TIA Portal project compiled without errors.

11.2 Power-On Steps

1. Power up ET 200SP station.
2. Verify PWR LED green on every BaseUnit.
3. Verify PWR + A-channel LED on AS-i Master 3RK7137-6SA00-0BC1.
4. Open TIA Portal, go online, and run Scan AS-i slaves.
5. Confirm the detected list equals the planned list (count and addresses).
6. Click Store slave configuration.

11.3 Functional Verification

• Force %Q1.4 (open command for slave 12) from the watch table.
• Verify the valve actuator physically moves within 2 s.
• Read %I1.4 and %I1.5 to confirm feedback transitions.
• Repeat for a sample of valves across all 48 addresses.
• Disconnect one valve, confirm BF LED flashes and OB82 is triggered.

12. FAQ