Adding CPU 313C 6ES7 313-5BG04-0AB0 to STEP 7 V5.5 HW Catalog

Problem Overview

When configuring a SIMATIC S7-300 station in SIMATIC Manager STEP 7 V5.5, attempting to insert a CPU 313C with order number 6ES7 313-5BG04-0AB0 into the hardware catalog fails because the module is not present in the right-hand catalog pane of HW Config. Repeated execution of Options › Install HW Updates does not add the part. Selecting Target System › Install HW Updates with an online connection to the Siemens update server also fails to surface the module. The CPU slot in rack 0 stays empty and the search field returns no matching order number.

The same project, opened on a different engineering PC with an updated STEP 7 V5.5 + SP4 + HSP bundle, immediately displays the module. The difference is the local Hardware Support Package (HSP) database that HW Config keeps under the STEP 7 install tree.

Root Cause Analysis

STEP 7 V5.5 ships with a hardware catalog snapshot taken at the time of the disc/release build. Newer S7-300 CPU variants introduced after that snapshot are not present in the local catalog database. The CPU 313C (6ES7 313-5BG04-0AB0) is one of the entries that has been re-released multiple times, and the 5BG04 variant ships in the more recent cumulative HSP for STEP 7 V5.5. If the install of the HSP failed silently, the descriptor is missing.

Three root causes are commonly observed:

1. Descriptor file not present in the local HWUpdate directory. The Online Update routine downloads the HSP archive into the STEP 7 install tree at ...\Siemens\Automation\SIMATIC Manager\HWUpdate. If this folder is read-only (common with UAC, domain-joined PCs, or installation under Program Files (x86)), the update completes the UI handshake but never writes the descriptor file. Subsequent searches in HW Config return no result.
2. Wrong MLFB mapped in the catalog. The 313C family spans 5BF03, 5BG04, 5BJ06, and 5BE01. They are not interchangeable. If a previous project on the same engineering PC used a 5BF03 variant, the local catalog may already contain a 313C entry, but with the wrong MLFB. STEP 7 does not perform MLFB auto-correction; it only enumerates exact matches against the descriptor table.
3. Online update server unreachable or proxy-blocked. The Online Update path requires https://support.industry.siemens.com access. If the engineering PC is on an isolated network, only manual HSP installation is possible.

Each module in HW Config is backed by a *.desc descriptor that encodes order number, firmware revision, integrated I/O ranges, default addresses, diagnostic behavior, and parameter assignment. The descriptor is the authoritative registration entry. Without it, HW Config cannot render the module, and Update Catalog cannot index it.

Prerequisites

• Local administrator rights on the engineering PC.
• STEP 7 V5.5 with the latest Service Pack installed (V5.5 SP4 or later recommended).
• All STEP 7 components closed before editing the HWUpdate directory.
• Offline HSP file or HTTPS access to support.industry.siemens.com.
• Write permission to the STEP 7 installation tree. If running on Windows 7/10/11 with UAC, the HWUpdate folder may be write-protected even for administrators. A workaround is to copy the HSP to a writable folder (e.g., C:\Temp\HSP_CPU313C) and install via Copy from Disk.
• Know the STEP 7 install path: typically C:\Program Files (x86)\Siemens\Automation\SIMATIC Manager (32-bit install) or C:\Program Files\Siemens\Automation\SIMATIC Manager (64-bit OS, 32-bit install).

STEP 7 V5.5 Hardware Catalog Mechanics

HW Config uses three layers to populate the right-hand catalog pane:

The Update Catalog command re-indexes layers 1 and 2 into a single searchable list. If layer 2 is empty or missing the descriptor for 6ES7 313-5BG04-0AB0, the module cannot be found regardless of the online update result.

Descriptors are validated by checksum. If a corrupt *.desc is present, HW Config silently skips it; this can mislead an engineer into believing the module is not yet supported when in fact the descriptor is damaged.

Step-by-Step Solution

1. Acquire the Hardware Support Package

Open a browser and navigate to the Siemens Industry Online Support portal:

1. Browse to support.industry.siemens.com.
2. Search for HSP STEP 7 V5.5 S7-300 or navigate via Product Support › Automation Technology › SIMATIC › PLC › S7-300.
3. Download the cumulative HSP archive (typically named HSP_S7_300_Vxxx.zip). Save it to a local working folder such as C:\Temp\HSP_CPU313C\.
4. Extract the archive. Inside you will find one or more *.hsp files and supporting *.desc files.

2. Identify the Correct Descriptor

Locate the descriptor file for the target CPU. The naming convention is one of:

• 6ES7313-5BG04-0AB0.desc
• CPU313C_5BG04.desc
• S7300_CPU313C_5BG04.hsp (a binary HSP that internally contains the descriptor)

Open the descriptor in a text editor and verify that the first line includes the literal order number 6ES7 313-5BG04-0AB0. If you see a different MLFB, you have the wrong file.

3. Place the Descriptor in the HWUpdate Folder

Copy the descriptor (and any companion *.hsp) to the STEP 7 HWUpdate directory:

If the directory is write-protected, copy the files to a local folder and reference that folder in step 4. The folder must contain the descriptor file directly; subfolders are not scanned by STEP 7.

4. Run "Install HW Updates" from Disk

1. Start SIMATIC Manager.
2. Open HW Config for the target station (or open a blank station to access the menu).
3. From the menu bar, click Options › Install HW Updates.
4. In the dialog, select the option Copy from Disk.
5. Click Browse and select the folder containing the descriptor (either the local HWUpdate directory or your C:\Temp\HSP_CPU313C folder).
6. Click Install.

STEP 7 reads the descriptor, validates the checksum, and queues the module for catalog registration. The status line should display Hardware updates successfully installed. Do not interrupt the install; a partial write can corrupt the catalog index and require a re-install of STEP 7.

5. Update the Catalog

After the install completes, refresh the catalog:

1. In HW Config, click Options › Update Catalog.
2. Wait for the index rebuild. The dialog may run for 10–60 seconds depending on the size of the local HSP archive.

The CPU 313C (6ES7 313-5BG04-0AB0) should now appear in the right-hand pane under:

6. Place the CPU in the Rack

1. Drag the CPU 313C entry into slot 2 of rack 0.
2. STEP 7 auto-populates the integrated I/O submodule structure for the CPU 313C.
3. Right-click the placed CPU and select Object Properties to confirm the order number is 6ES7 313-5BG04-0AB0.
4. Save and compile the hardware configuration (Station › Save and Compile).

Verification

1. Confirm the order number shown under Object Properties › General › Order Number matches the physical CPU front label.
2. Save and compile the project. The diagnostic log should report no errors.
3. In the project tree, confirm that the integrated I/O symbols are populated:
   · 24 digital inputs (default addresses IB 0, IB 1)
   · 16 digital outputs (default addresses QB 0, QB 1)
   · 5 analog inputs (default addresses PIW 128, 130, 132, 134, 136)
   · 2 analog outputs (default addresses PQW 128, 130)
4. Download the configuration to the target CPU (online connection via MPI/PROFIBUS).
5. Switch the CPU to RUN. The SF LED must be off and the RUN LED must be solid green.
6. Open PLC › Module Information › Diagnostic Buffer. The buffer should not contain entries with the cause Module does not exist or Type identifier invalid.

CPU 313C 6ES7 313-5BG04-0AB0 Specifications

The CPU 313C is a single-width module that occupies slot 2 of the S7-300 rack. It hosts a PROFIBUS DP interface on the front X2 connector. The front X1 connector (24 V DC) supplies power to the integrated I/O and counters.

Firmware Update Procedure (CPU Side)

Siemens periodically releases firmware updates for the 6ES7 313-5BG04-0AB0. The official entry point is the Siemens support article:

Firmware updates for CPU 313C (6ES7313-5BG04-0AB0)

To update an online CPU through STEP 7 V5.5:

1. Start STEP 7 and switch to HW Config.
2. Open the station that contains the CPU 313C.
3. Highlight the CPU slot.
4. Select Target System › Update Firmware.
5. Browse to the downloaded firmware file (e.g., CPU_313C_V33_Upd1.upd).
6. Confirm. The CPU automatically resets and restarts in RUN with the new firmware.

Notes:

• A firmware update is non-reversible to a version older than the active one. Downgrade protection is enforced.
• The MMC is not erased. The user program and project data persist.
• Interrupting the update (power loss, MPI cable disconnect) can leave the CPU in a non-bootable state. Recovery requires a re-flash from STEP 7 with the original firmware image and an MMC formatted for the CPU.
• For TIA Portal users, the procedure is documented in the TIA manual collection under Online and Diagnostics › Updating Firmware (see the TIA Portal manual at docs.tia.siemens.cloud).

Related CPUs in the 313C Family

If the physical CPU in your panel has a different MLFB printed on the front, you must use the matching catalog entry. Cross-check the order number on the front label against the order number configured in HW Config. The Properties dialog must show the same number as the label.

Diagnostic Buffer and Status LED Reference

Diagnostic events are read via PLC › Module Information › Diagnostic Buffer in SIMATIC Manager. The buffer is non-volatile and survives power cycles, so field engineers can read the last fault after a power-down.

Troubleshooting Matrix

Compatibility and Migration Notes

• The 6ES7 313-5BG04-0AB0 is fully compatible with S7-300 I/O modules and FM/CP modules. The integrated I/O cannot be used at the same addresses as external modules; address ranges must not overlap.
• Maximum central rack configuration: 1 power supply (PS), 1 IM (if used), up to 8 signal modules (SM), 1 FM, 1 CP, plus the CPU. Beyond 8 SM, an expansion rack via IM 360/361 is required.
• The CPU is a DP-V0 master/slave. It does not support DP-V1 or DP-V2 by default. Check the firmware release notes for V3.3.x extensions if DP-V1 is required.
• MPI address range is 0–31. Default is 2. Each CPU on the bus must be unique.
• For TIA Portal users, import the STEP 7 V5.5 station via Migrate to TIA Portal. The CPU 313C is supported in TIA V13 SP1 and later. The portal reuses the same HSP catalog that STEP 7 V5.5 keeps.
• When migrating an S7-300 project that uses the integrated counter channels to TIA Portal, the counter configuration is preserved but the data block offsets may shift. Verify counter configuration under CPU Properties › Counter after migration.
• Older 5BF03 projects that referenced EPROM operation must be rewritten for MMC. The startup OB 100 behavior is preserved.

Opening a Siemens Support Request

If the descriptor for the 6ES7 313-5BG04-0AB0 cannot be located in any public Siemens download, or if the online update server returns error codes such as 0x800F0922 (Windows update failure) or HTTP 403, open a support request at:

support.industry.siemens.com

Include the following in the request:

• Exact order number and firmware version printed on the CPU front panel.
• STEP 7 version (e.g., V5.5 SP4) and the applied Service Pack.
• A screenshot of the HW Config catalog pane showing the missing module.
• The exact filename of the descriptor placed in the HWUpdate folder.
• Content of the diagnostic buffer if the CPU is online.

FAQ