Reading ET200SP HA Channel & Module Diagnostics in PCS 7 V9.0 SP2

Reading ET200SP HA Channel & Module Diagnostics in PCS 7 V9.0 SP2

Channel-level and module-level diagnostics for SIMATIC ET 200SP HA remote I/O stations on a redundant CPU 410-5H automation system are generated automatically by the PCS 7 V9.0 SP2 Advanced Process Library (APL). The default @charts of every process tag already contain the channel driver instance, the alarm logic, and the operator messages required by Planning the configuration of an ET 200SP HA distributed I/O - no custom diagnostic block programming is required for the standard process alarms such as wire break, short circuit, underrange, and overrange.

This tutorial consolidates the PCS 7 APL mechanism, the underlying PROFINET IO diagnostic data records defined for the SIMATIC ET 200SP HA Technology Modules manual, and the asset-management view provided by the Maintenance Station option. The goal is to make module and channel diagnostics visible both in the WinCC operator station and on the diagnostic screens produced by the Maintenance Station, on a CPU 410-5H redundant AS running PCS 7 V9.0 SP2.

1. System Prerequisites and Licensing

Before you plan diagnostics, the engineering station, the AS 410H pair, and the operator station must satisfy the following minimum configuration.

2. Automatic Diagnostics via APL Channel Drivers

When you compile the CFC chart of a process tag (e.g. Pcs7AnIn, Pcs7DiIn, Pcs7AnOu, Pcs7DiOu, Pcs7Mot, Pcs7Valve), PCS 7 does the following automatically:

1. Generates the driver instance in the unit-level @chart (for example Unit1/AI_101 → instance DB DB1001).
2. Generates the alarm and message logic including the standard process alarms "Failure", "Upper limit violated", "Lower limit violated", "Bad quality", and the channel-diagnostic alarms "Wire break", "Short circuit", "Underflow", "Overflow".
3. Wires the channel-diagnostic input of the driver to the value status (QUALITY_BAD, bit 0x40 "Channel diagnostic available") of the input/output address from the PROFINET IO frame.
4. Creates the corresponding WinCC message in the OS project, with the message class, priority, and the operator text configured in the APL block icon properties.

Therefore no additional program code is required in the @chart to obtain wire break, short circuit, and overflow alarms for a standard channel. The diagnostics are read by the PROFINET IO stack of the CPU 410-5H from the channel-specific diagnostic data records (DS 100) of the ET 200SP HA module and are forwarded to the OS as channel diagnostic alarms.

3. APL Channel Driver Block Reference

The following APL blocks implement the standard channel driver with full diagnostic evaluation. Use the version that ships with the APL V9.0 SP2 master data library.

For the full list of block numbers, signal pin names, and the runtime licence per channel driver see the PCS 7 V9.0 SP2 APL Function Manual shipped on the PCS 7 installation media (entry ID 109811210 in the Siemens Industry Online Support).

4. @Charts Architecture and Driver Instances

Every PCS 7 plant unit contains an automatically generated @chart (driver chart). The chart holds one instance of the channel driver per process tag of the unit and a single instance of MOD_PREP plus the S7 standard blocks OB_BEGIN, OB_END, and (if redundancy is enabled) RED_AGO / RED_ANA. A simplified view of a single unit is shown below.

To make the channel diagnostics visible in the OS, set the following attributes in the block icon properties of the channel driver:

• Message class: Process - Failure or Process - Warning depending on the alarm category.
• Operator text: &1 &2 failed: channel &3, slot &4 (substitutes the tag name, unit, channel and slot at runtime).
• Acknowledgement: enabled for the "Failure" class, disabled for warnings such as wire break if the HCI / Maintenance policy is configured to treat them as a non-ack warning.

5. Module and Channel Diagnostics Data Records

The ET 200SP HA modules expose a defined set of PROFINET IO diagnostic data records. The CPU 410-5H reads them on demand and on diagnostic interrupt; the values are the source of the "Bad quality" bit and the channel-diagnostic alarms seen on the OS. The data records most relevant to operator-visible diagnostics are listed below; refer to the SIMATIC ET 200SP HA Technology Modules manual for the full set and the byte layout.

6. Reading Diagnostics with SFB 52 / SFB 81

Although the standard process alarms are generated automatically, two scenarios still require an explicit read:

1. Operator-triggered module information from a custom WinCC dialog.
2. Custom maintenance logic that has to decide between two state categories (for example "warning" vs "failure") based on the maintenance information in DS 200.

Use the standard S7 system blocks - no proprietary block has to be written. The required SFBs are part of the CPU 410 firmware and are therefore available without a licence.

A minimal Structured Text wrapper for reading the channel diagnostic record of a digital input module is shown below. The block can be instantiated as a function block in the unit chart or in a dedicated "diagnostics" chart at plant level.

FUNCTION_BLOCK FB_RdChannelDiag
VAR_INPUT
  hwId      : DWORD;   // HW identifier of the slot, e.g. DW#16#0000012C = 300
  recIndex  : BYTE;    // 100 = 0x64, channel diagnostics
END_VAR
VAR_OUTPUT
  status    : WORD;    // RET_VAL of RDREC, 0 = no error
  busy      : BOOL;
  done      : BOOL;
  error     : BOOL;
  diagBytes : ARRAY[0..63] OF BYTE;
END_VAR
VAR
  rdrec     : RDREC;   // SFB 52 instance
  start     : BOOL;
  i         : INT;
END_VAR

// request trigger
start := NOT busy AND NOT done;
rdrec(REQ := start,
      ID  := hwId,
      INDEX := WORD#16#0064,    // DS 100 = channel diagnostics
      MLEN := 64,
      VALID := done,
      BUSY  := busy,
      ERROR := error,
      STATUS := status,
      RECORD := diagBytes);

After a successful read, decode diagBytes using the channel-diagnostic structure documented in chapter "Diagnostics / Alarms" of the ET 200SP HA configuration manual. Channel error codes 0x0001..0x000F (short circuit, wire break, underflow, overflow, parameterisation error) map to the channel alarm bits used by the APL drivers and the WinCC message system.

7. Maintenance Station: Basic vs Standard

The PCS 7 Maintenance Station is the asset-management view of the plant. It renders block icons for every AS, every PROFINET/PN IO device, and (with the Standard option) every ET 200SP HA station and I/O card, and updates the state in real time using the data records listed above.

To enable the Maintenance Station Standard:

1. In SIMATIC Manager, open the OS project, right-click the OS server and select Object properties → OS server → Maintenance Station.
2. Tick Maintenance Station Standard and enter the licence key in the "Authorisation" tab.
3. In HW Config of the AS, mark the IM 155-6 PN HA as "diagnostics-capable" and enable the data record reads on slot 0 and on every I/O slot.
4. Compile the OS - the compilation step automatically creates the block icons in the standard picture @Maintenance.pdl and adds the necessary WinCC tags under the Diagnostics\ prefix.

8. Step-by-Step: Make Channel Diagnostics Visible in PCS 7 V9.0 SP2

1. Compile the HW Config of the AS 410H with "Generate diagnostic data record reads = ON" for every ET 200SP HA head-end. The AS then reads DS 1, DS 12..15 and DS 200 cyclically (default 1 s).
2. Insert the APL channel driver in the unit chart: Pcs7AnIn, Pcs7DiIn, Pcs7AnOu, Pcs7DiOu, Pcs7Mot, Pcs7Valve - or one of the type-specific derivatives. Compile the chart. PCS 7 generates the @chart with the driver instance and the MOD_PREP block.
3. Set the message classes in the block icon properties. For channel diagnostics, the APL default of Process - Failure for wire break / short circuit and Process - Warning for underflow / overflow is appropriate for most process plants.
4. Download the AS program to the H-system. The PROFINET IO stack synchronises the channel-diagnostic information to the active CPU and the partner.
5. Compile the OS (full compile, not incremental). The new messages appear in the WinCC message configuration; the new variables appear under Diagnostics\<unit>\.
6. Open the OS Runtime and acknowledge the test alarm triggered by pulling the sensor wire on a digital input channel. The corresponding message "Wire break DI_202 / channel 5" should appear in the message line and the Maintenance Station view should switch the block icon of slot 5 to "Maintenance demanded".

9. Verification Checklist

Run the following verification matrix before signing off the diagnostics configuration on a CPU 410-5H AS.

10. Troubleshooting Matrix

11. Field-Commissioning Notes

• CFC compile order. Compile the unit charts before the @chart is generated. The @chart depends on the chart-folders of the unit; an out-of-order compile creates a @chart with missing channel-driver instances.
• I&M data. Fill the I&M 1, I&M 2, I&M 3 fields per module before the first cold start. The Maintenance Station Standard depends on I&M 1 ("Location") to render the asset tree correctly.
• OS redundancy. If the OS server is redundant, the Maintenance Station views are mirrored automatically. Verify the Diagnostics\ tag prefix is identical on both servers, otherwise messages from the partner server will be tagged as "Unknown".
• PROFINET update time. The default update time of 1 ms for the IM 155-6 PN HA may be too aggressive for analog channels. Use 2 ms for AI/AO channels in the process industry, and 1 ms only for fast DI/DO. See Reading out the diagnostics in STEP 7 (TIA Portal).
• Cybersecurity. Channel diagnostic reads use plain S7 communication. If the AS is on a security-zoned network, open the firewall only for S7 port 102 and the PROFINET-RT class 1 multicast ranges.

FAQ