Resolving ET200SP HA DI 32 Address Space: PI vs Value Status

Overview: Why a 32-Channel ET 200SP HA DI Module Occupies 8 Bytes

The SIMATIC ET 200SP HA distributed I/O system is engineered for process automation in hazardous areas and is fully integrated into PCS 7 and STEP 7 (TIA Portal). The DI 32x24VDC HA digital input module, identified by article number 6DL1131-6BL00-0PH1, provides 32 galvanically-isolated 24 VDC input channels in a single ET 200SP HA slot. It is typically deployed on a station headed by the IM 155-6 PN HA interface module (6DL1155-6AU00-0PM0 or 6DL1155-6BU00-0PM0) and connected to a CPU 410-5H (6DL7410-5HR06-0EX0) acting as the PROFINET IO Controller.

When the module is dropped into the device view of HW Config (STEP 7 V5.x) or Tia Portal, the address range for the slot expands to 8 bytes (64 bits). This is the first source of confusion: a 32-channel module should logically consume 4 bytes, not 8. The extra 4 bytes are not a configuration error, and they are not additional input channels. They are the PROFINET value status (also called QI or Quality Information Byte, bound to the ProImQB parameter of the Pcs7DiIn block) that reports, per channel, whether the read value is valid.

Understanding this split is essential before wiring the symbol table, generating PCS 7 driver blocks, or writing CFC code that reads I 4.x and I 5.x directly. The remainder of this guide defines the exact address map, explains how the value status is wired to the Pcs7DiIn driver block via the ProImQB parameter, and walks through commissioning in both STEP 7 V5.x and Tia Portal.

Module Identification and Variants

Siemens uses a consistent article-number pattern for the SIMATIC ET 200SP HA digital input family. The '6DL' prefix denotes SIMATIC PCS 7 / process automation catalog items, the '1311' group is digital inputs, and the suffix differentiates channel count and module revision.

The corresponding device manual is the ET 200SP HA DI 16x24VDC HA device manual (PDF, 6DL1131-6BH00-0PH1), which documents the same architectural principles for the 16-channel member of the family. The 32-channel module follows the identical I/O model, scaled by a factor of two. The official SIMATIC ET 200SP manual collection (TIA Portal cloud) covers address-space planning for the hazardous-area modules including the 27 VDC variants.

Address Space Architecture: Process Image Versus Value Status

Every PROFINET-capable Siemens I/O module separates the user data (process image) from the diagnostic data (value status). For a digital input module the user data is one bit per channel; the value status is also one bit per channel, but it is exposed in a separate byte area so that the controller can poll diagnostics independently from the cyclic I/O update.

The DI 32x24VDC HA returns 8 bytes of inputs per slot, divided as follows:

• Bytes 0 to 3 (Input address a.0 to (a+3).7) — process image (PI) of channels 0 to 31. Bit n of byte m corresponds to channel (m * 8) + n.
• Bytes 4 to 7 (Input address (a+4).0 to (a+7).7) — value status (QI / ProImQB) for channels 0 to 31. Bit n of byte (m+4) is the value status of the same channel addressed by bit n of byte m.

The 'a' in the address column depends on the start address of the slot. If the slot is configured to start at input address 0, the first input is I 0.0 (channel 0) and the last value status bit is I 7.7 (status of channel 31). If the slot starts at input address 16, the first input is I 16.0 and the last value status bit is I 23.7. The mapping is a fixed offset of +4 bytes between PI and QI; it cannot be changed in the module properties.

Address Layout Diagram

Value Status (ProImQB) Semantics

Value status is a PROFINET-defined feature carried in the input data of every channel. The bit follows the IEC 61784-2 PROFINET specification:

• Value status = 1 — the channel is providing a valid process value. The bit in the process image (PI) reflects the actual hardware state at the terminal.
• Value status = 0 — the channel is faulty, the module has channel-level diagnostics active, the value is substituted (forced to 0), or the channel is deactivated. The PI bit in this case is not reliable.

The value status is generated by the module's firmware and is updated cyclically on the same PROFINET cycle that carries the process image. It does not require any additional configuration in the module properties; it is always on for PROFINET devices in the ET 200SP HA family. The configuration of channel-level diagnostics (wire break, short circuit, supply voltage missing) is a separate step and is found in the module's 'Parameters' tab in HW Config or Tia Portal.

Why the Pcs7DiIn Driver Block Uses ProImQB

PCS 7 uses a standardized channel driver block, Pcs7DiIn, to bring the digital input into the user program. The block has a process input (PI) and a process output that is usually wired to the technology block (e.g., MotSpeed, VlvAn, MonAn). The ProImQB parameter on Pcs7DiIn is the value status (Process Image Quality Bit) of the process image bit. The block also exposes the QBAD output, which goes to 1 when ProImQB is 0.

When you run the PCS 7 'Generate Module Drivers' wizard, the wizard scans each configured slot, identifies the channel driver block family (Pcs7DiIn for digital inputs), and automatically wires the value status bits (bytes 4-7) to the ProImQB parameter of the corresponding Pcs7DiIn block. The signal I/O (bytes 0-3) is wired to the PV (process value) input of the Pcs7DiIn block by the user, or by the IEA file if the signal list was imported.

For the 6DL1131-6BL00-0PH1 module the wiring table produced by the wizard is:

The 'a' is the start address configured in HW Config. The wizard uses the module's GSD file (GSDML-V*-Siemens-ET200SPHA-*) to read the assignment between input bit and channel, so the engineer does not need to compute the address manually.

Configuration in STEP 7 V5.x (HW Config)

The following procedure applies to PCS 7 V8.x or V9.x with STEP 7 V5.6 and the ET 200SP HA library installed.

1. Open the S7 program and double-click the ET 200SP HA station in the component view.
2. Insert the DI 32x24VDC HA from the hardware catalog under 'ET 200SP HA > DI'. Drag it to the desired slot of the IM 155-6 PN HA interface module.
3. Double-click the inserted module. In the 'Addresses' tab, set the start input address. PCS 7 typically places the module in the address range reserved for I/O (default 0..255). Confirm that the input length shows 8 bytes.
4. Switch to the 'Parameters' tab. For each of the 32 channels, you can enable wire-break detection, short-circuit detection to 24 V, input delay (0.05 ms / 0.1 ms / 0.5 ms / 3 ms / 15 ms / 20 ms), and the value status (always on for PROFINET, but the parameter is still exposed for documentation).
5. Compile and download the hardware configuration (HW Config > Station > Save and Compile > PLC > Download to Target).
6. Open the CFC chart that owns the digital inputs. From the PCS 7 menu, run 'Options > Plant View > Generate Module Drivers'. The wizard will create one Pcs7DiIn block per channel and wire the value status to ProImQB.
7. Compile the CFC chart and download to the AS.

Configuration in TIA Portal (V15.1 and later)

From Tia Portal V15.1 onward, the ET 200SP HA is fully supported as a PROFINET device. The configuration flow is similar to HW Config but the terminology differs.

1. Open the Tia Portal project and navigate to 'Devices & Networks'.
2. Select the ET 200SP HA station and add the DI 32x24VDC HA from the device catalog.
3. In the device view, click the module. The 'I/O addresses' tab will display the start address and the length of 8 bytes in the input area.
4. Open the 'Properties > Module parameters' tab. The 32 channels are listed in a table; for each channel you can configure the input delay, the diagnostics (wire break / short circuit / missing supply), and the value status behavior.
5. For PCS 7 V9.0 SP2 and later that supports the TIA-based engineering, generate the driver blocks from the 'Generate Module Drivers' tool in the CFC editor; the wizard reads the GSDML of the device and wires ProImQB identically.
6. If you are using Tia Portal without PCS 7, the value status bits are not wired to a driver block. You must read bytes 4-7 explicitly in your user program and evaluate the value status in your own logic.

Reading Value Status Manually in SCL

If you are not using PCS 7, the value status can be read directly in the user program. The following Structured Control Language (SCL) snippet reads the 32 value-status bits of the DI 32 module starting at input byte 4 and aggregates them into a DWORD for use in your application code:

// Module slot start address: 0
// Value status starts at IB 4
// First 4 bytes (IB 0..IB 3) = process image of channels 0..31
// Last 4 bytes (IB 4..IB 7) = value status of channels 0..31

// Aggregate the 32 value status bits into a single DWORD
#ValueStatusDword := (BYTE_TO_DWORD(IB 4) AND 16#000000FF)
                OR (SHL(BYTE_TO_DWORD(IB 5) AND 16#000000FF, 8))
                OR (SHL(BYTE_TO_DWORD(IB 6) AND 16#000000FF, 16))
                OR (SHL(BYTE_TO_DWORD(IB 7) AND 16#000000FF, 24));

// Test the value status of channel 0
IF ((#ValueStatusDword AND 16#00000001) <> 0) THEN
    // Channel 0 value is valid
    #Channel0Valid := TRUE;
END_IF;

// Test the value status of channel 31
IF ((#ValueStatusDword AND 16#80000000) <> 0) THEN
    // Channel 31 value is valid
    #Channel31Valid := TRUE;
END_IF;

Can Bytes 4-7 Be Used as Additional Input Channels?

No. Bytes 4-7 are not user data. They are exclusively the value status. If you wire a sensor to terminals that correspond to channels 0-31, those signals appear in bytes 0-3 only. If you wire a sensor to a different module's terminals, those signals appear at that module's address range.

Attempting to read a real signal from I 4.0 will always return the value status of channel 0, not an additional input. The only valid use of bytes 4-7 is the value status, and the only valid destination in PCS 7 is the ProImQB input of the Pcs7DiIn block. Manually assigning I 4.0 in a CFC chart as a sensor input will overwrite the value status and break the quality information for channel 0.

Verification Procedure

Use the following checks to confirm that the module is wired correctly and the address mapping is intact.

1. Online > Monitor / Modify: Open the variable table for the AS and monitor the input bytes 0-3. Force a 24 V signal on terminal 1 of the module (channel 0) and verify that I 0.0 transitions from 0 to 1. Repeat for terminals 2 to 32 to confirm the channel-to-bit mapping.
2. Value status check: Monitor the value status bits (bytes 4-7). All 32 bits should read 1 for healthy, wired channels. If a value status bit reads 0, the corresponding channel is in a diagnostic state.
3. ProImQB monitoring: In the CFC online view, open the Pcs7DiIn block for channel 0. The ProImQB parameter should mirror the value status bit I 4.0. Toggle the input and verify that the ProImQB value remains 1.
4. Diagnostic simulation: Disconnect the sensor wire from channel 0. The input I 0.0 should go to 0 and the value status I 4.0 should go to 0 within one PROFINET cycle. The ProImQB of the corresponding Pcs7DiIn block should also go to 0, and the QBAD output of the block should activate.
5. Module diagnostics buffer: In the online diagnostic view of the module (right-click > Module Information > Diagnostics Buffer), confirm that the slot reports 'OK' for the wired channels and 'Channel fault' for the disconnected channel.

Troubleshooting Matrix

Comparison with the 16-Channel Variant (6DL1131-6BH00-0PH1)

The 16-channel DI module follows the same architectural rule, scaled by a factor of two. Its slot consumes 4 bytes of input address: 2 bytes of process image (bytes 0-1, channels 0-15) and 2 bytes of value status (bytes 2-3). The 16-channel device manual is available at the official Siemens support portal (PDF, 6DL1131-6BH00-0PH1). Use the same procedure to read the value status of the 16-channel module: shift the result by two bytes, since the value status starts at byte 2 of the slot rather than byte 4. The same ProImQB wiring logic in PCS 7 applies.

The 24/27 VDC variants (6DL1131-6TH00-0PH1 for 16 channels at NAMUR, 6DL1131-6TL00-0PH1 for 32 channels at 24 VDC) follow the identical PI/QI split. The 24 VDC high-feature module (6DL1131-6BL00-0PH1 in the 'Type 3' design) supports value status with per-channel diagnostic interrupts that propagate to the OB 82 diagnostic interrupt on the CPU 410-5H.

Field Commissioning Notes

During loop checks, the value status of an unwired terminal will read 0, not 1, because the input is in an undefined state. This is the desired behavior — it tells the operator that the channel has not been commissioned yet. Some integrators prefer to force the value status to 1 for unwired channels during commissioning, but this is not a native module feature; it requires the application logic to override the QBAD output of the Pcs7DiIn block, or to install a physical loop-back (resistor) on the terminal that sources the minimum current required by the input.

Wire-break detection requires the sensor to source a defined current out of the terminal. A simple dry contact without a 24 V pull-up cannot be diagnosed as wire break; the module will only see the input state. For dry contacts, use a base unit with the appropriate wiring and ensure that the 'Wire break' diagnostic is disabled, otherwise the value status will read 0 continuously and QBAD will be active on the corresponding Pcs7DiIn block.

For PROFIsafe applications, the DI 32 module is paired with a F-CM (fail-safe communication module) and the station is configured as a PROFIsafe device on the F-CPU. In those configurations, the value status bits are consumed by the F-host and are not exposed to the standard Pcs7DiIn block. The fail-safe driver block (Pcs7FDiIn) is used instead, and the value status is read via the PROFIsafe telegram, not via the cyclic input area.

For redundant CPU 410-5H configurations, both H-CPUs receive the full 8-byte input area from the ET 200SP HA station over the PROFINET ring. The Pcs7DiIn blocks are instantiated on the active master; the value status logic is identical. If the station is configured as a shared device on both H-CPUs, address the modules in the device view of each H-CPU separately and ensure that the GSDML import is repeated for both.