Integrating ABB S800 I/O with Siemens S7-300 via PROFIBUS DP

System Overview: ABB S800 I/O on a Siemens PROFIBUS Master

The ABB S800 I/O platform is widely deployed in process plants where ABB System 800xA, Advant Master, AC450, or Freelance DCS controllers pair with S800 modules. The CI830 (order code 3BSE013262R1) is the PROFIBUS DP-V1 communication interface that lets the same S800 family be reached from a third-party master such as the Siemens SIMATIC S7-300 CPU 315-2DP. From the Siemens perspective, the CI830 behaves as a standard DP-V0/V1 slave; from the ABB side it acts as a ModuleBus master to up to twelve S800 I/O modules (DI810, DO810, AI810, AO810, AI830, AO845, DX820, etc.).

When an S7-300 is the PROFIBUS master, every CI830 shows up in HWConfig as a DP slave with twelve empty slots that map one-to-one to the physical ModuleBus positions on the right-hand side of the CI830. Misalignment between the slot list inside HWConfig and the physical module arrangement is the single most common reason that "everything is configured but the Fault LEDs stay on," which is exactly the symptom observed when a CPU 315-2DP and a CI830 SW*1.3 were first wired together.

Prerequisites: Hardware, Firmware, and Software

GSD File Selection and Installation in SIMATIC Manager

The CI830 GSD identifies the device to STEP 7 with PROFIBUS Ident Number 0x0F70. ABB publishes firmware-keyed GSDs: a v1.3 GSD for legacy modules and a v1.4 GSD for current production. Both work, but the GSD must match the firmware burned into the CI830; a v1.4 GSD downloaded against a v1.3 module produces parameter negotiation failures that look identical to a wiring or slot-mismatch fault.

1. Close every instance of SIMATIC Manager and HWConfig.
2. Copy the GSD file (ABB_0F70.GSD) and the associated bitmap (ABB_0F70.bmp) into <STEP7>\S7DATA\GSD.
3. Start SIMATIC Manager → Options → Install GSD File… → browse to the GSD.
4. Wait for the catalog rebuild to finish; this may take 30-60 s on older workstations.
5. Open HWConfig and confirm the new slave appears under PROFIBUS DP → Additional Field Devices → I/O → ABB.

For very old projects that still use the older catalog layout, the CI830 sometimes appears under PROFIBUS DP → Other Field Devices → ABB → S800 → CI830. The path is cosmetic; the slave Ident Number 0x0F70 is what the master uses during parameterization and is what matters at runtime.

HWConfig Network Topology and Slave Insertion

Open HWConfig for the S7-300 station, double-click the DP interface row of the CPU 315-2DP, and set the master address (default 2) and the operating mode DP Master. On the PROFIBUS line, drag the CI830 symbol from the catalog onto the bus and assign the slave address that matches the rotary DIP switches on the module (3 in the reference configuration).

Set the baud rate to a value supported by every segment. For a short panel cable, 1.5 Mbps is typical; for plant wiring that exceeds 100 m, drop to 500 kbps or 187.5 kbps. The CI830 auto-detects baud rate from the master's parameterization frames, so no baud switch is required on the module itself.

Critical Step: CI830 Slot Assignment and Parameter Positions

This is the step that the original integrator missed and the root cause of the persistent Fault LEDs. The CI830 exposes twelve slots in HWConfig (slots 1–12; slot 0 is occupied by the CI830 itself). Slots 1–12 represent the ModuleBus positions that physically sit on the right-hand side of the CI830 baseplate.

For each populated position you must:

1. Insert the matching S800 module (DI810, DO810, AI810, AO810, …) into the correct HWConfig slot — slot 1 = leftmost physical position, slot 2 = next to it, and so on.
2. Double-click the inserted module to open the Properties – DP Slave dialog.
3. Switch to the Parameter Assignment tab.
4. Set the ModuleBus Position (also called "Position" or "Slot Index") to the same number as the HWConfig slot. Modules shipped from ABB default to position 1.
5. Save the slot and repeat for every physical module.

If two slots share the same position, the CI830 reports a configuration mismatch and every affected I/O module lights its Fault LED red. If a HWConfig slot is left empty while the physical position is populated, the CI830 raises the same diagnostic against the physical module. Either way, the user's observation that "both Fault lamps are ON while Power on the CI830 is green and both Tx and Rx are steady yellow" is the canonical signature of a configuration error during the parameterization phase, not a wiring error.

Note also that an empty HWConfig slot is not an error — the CI830 accepts gaps in the slot list, and so does the S7-300 master. What you cannot do is assign two modules to the same slot index, or place a module in a slot index that is empty on the baseplate.

PROFIBUS Address and Baud Rate Configuration

The CI830 station address is set with a rotary switch on the front of the module. Address 0 is reserved for master-class operation; addresses 1–125 are valid slave addresses per IEC 61158. Address 3 used in the reference configuration is legal, but it must not collide with the master address (2) or with any other slave on the segment. The DIL switch has 8 bits; the LSB is switch 1 and the MSB is switch 8. The resulting address is read at power-on; changing the address requires a power cycle of the CI830.

Use this binary-to-decimal mapping to set the switch:

Address = Σ (switch_i × 2^(i-1))   for i = 1..8
Example: switches 1+2 ON, others OFF → 1×1 + 1×2 = address 3

The baud rate is not switched on the CI830; the slave auto-detects the master's baud rate from the received parameterization telegram. Make sure the master's profile supports the rate you selected (e.g. "DP, 1.5 Mbps" in HWConfig → Properties → Network Settings).

LED Diagnostics: Decoding Tx/Rx/Fault Behavior

The CI830 has four front-panel LEDs that map cleanly to PROFIBUS DP state. The combination described by the integrator — Power ON, Tx and Rx steady yellow, Fault ON on the S800 modules — is a configuration error during Wait_Cfg, not a physical-layer fault.

On the S800 I/O modules (DI810, DO810, …):

PROFIBUS Analyzer-Based Debugging

If the Fault LEDs persist after the slot/position alignment, capture the PROFIBUS frames during startup. Tools such as the Softing PROFIBUS Inspector, Indu-Sol PROFIBUS-INspektor NT, or Siemens BT200 tap the segment in parallel (in-line tap or at the diagnostic connector) and decode every master/slave telegram. This is the fastest way to discriminate between parameterization, configuration, and application-layer failures.

Frames to Capture

• Set_Slave_Address (SSA) — broadcast from the master in the parameterization phase; sometimes disabled depending on master profile.
• Parameterization (Prm) — the master tells each slave its address, watchdog, and Ident Number. The slave replies with Prm_Res; a reject raises diagnostic byte 0x0A.
• Check_Cfg — the master tells each slave which slots are populated and with what I/O lengths. The slave replies with Check_Cfg_Res; a mismatch raises 0x0B "Configuration Error".
• Slave_Diag — slave-initiated diagnostics with the standard PROFIBUS DP diagnostic header (first byte 0x08 = station_status_1).
• Data_Exchange — cyclic I/O; absence of Data_Exchange frames after a successful Cfg handshake indicates that the CI830 is healthy but the I/O modules are not.

Diagnostic Byte Mapping

A typical "Fault LED on every I/O module" capture looks like this:

1. Master → Slave: Prm with Ident Number 0x0F70, accepted.
2. Master → Slave: Check_Cfg listing slot 0 = CI830, slot 1 = DI810 (4 bytes I), slot 2 = DO810 (2 bytes O), slots 3-12 empty.
3. Slave → Master: Check_Cfg_Res negative (configuration error).
4. Slave → Master: Slave_Diag with station_status_1 = 0x04 and extended diagnostic bytes identifying the offending slot.
5. Master retries every bus cycle; Tx and Rx on the CI830 stay lit because it is constantly retransmitting.

If the analyzer instead shows Prm_Res negative with 0x40, the Ident Number is wrong — you loaded the wrong GSD for the firmware. Reload the matching GSD and rebuild the catalog.

Compilation, Download, and Online Verification

1. Save and compile HWConfig (Station → Save and Compile → All). The compile log must report No errors; warnings about "consistent I/O lengths" can usually be ignored.
2. Download HWConfig to the CPU (PLC → Download). The CPU goes into STOP briefly and returns to RUN with the new PROFIBUS configuration.
3. Go online (PLC → Connect to Target System → PROFIBUS). Right-click the CI830 row → Slave Diagnostics. The diagnostic buffer must show Configuration OK and the I/O modules must report No fault.
4. In the S7 program, map the I/O areas. By default the CPU assigns:
   • DI810 to inputs IW 0..IW 1 (16 bits packed in 2 bytes).
   • DO810 to outputs QW 0..QW 1.
5. Force a digital output on the DO810 (SET QW 0 or via VAT/PLC → Monitor/Modify) and read back the corresponding input on the DI810 to close the loop.

Troubleshooting Matrix

Field-Proven Caveats and Version Compatibility

• GSD vs. firmware. v1.3 and v1.4 GSDs are not interchangeable. A v1.4 GSD loaded against a v1.3 module will pass Check_Cfg but fail during the user-parameter handshake; the symptom is identical to a slot-mismatch fault.
• Empty slots are allowed. Leaving HWConfig slots 3–12 empty does not produce a Fault LED, as long as the physical positions 3–12 are also empty. If you populate a physical slot without a matching HWConfig entry, the CI830 reports a configuration error against the slot itself.
• ModuleBus termination. The last S800 module on the baseplate must have a termination plug (TU811 or TU813) inserted in the unused end connector. Without it, modules at the far end of the chain report intermittent faults that look like configuration errors but happen only at certain baud rates.
• Hot-swapping. The CI830 supports hot-removal of I/O modules only if the slot is empty in HWConfig. Removing a module whose slot is configured causes the CI830 to raise an ext_diag "module missing" and any process image mapping to that module will freeze at the last value.
• CPU 315-2DP variants. The CPU 315-2DP comes in several MLFB variants; all of them support the CI830, but only the -2AG10 and later revisions support DP-V1 class 2 read/write services. If you only need DP-V0 cyclic I/O, any 315-2DP works.
• STEP 7 version. STEP 7 V5.5 SP2 or later is recommended. STEP 7 V5.4 will load the CI830 GSD but may not display the ModuleBus Position parameter correctly in HWConfig; you would have to drop into the object properties (DP slave → Object Properties → Parameter Assignment) to set it manually.
• Cross-vendor best practice. When integrating ABB S800 with Siemens masters, always define the slot list in a separate project first, export it as a "type file", and import it into each station. This avoids drift between the HWConfig slot index and the CI830 ModuleBus Position across multiple stations.
• SF LED on the CPU. If the CPU 315-2DP shows a steady SF (red) after the download, the CPU has detected a DP slave failure. Open PLC → Diagnostics/Setting → Hardware Diagnostics to see which slave is missing; do not clear the diagnostic buffer until you have written down the slave address and the event ID.
• PROFIBUS vs. PROFINET. The CI830 is PROFIBUS DP only. If the S7-300 is a CPU 315-2PN/DP, you still need to wire the CI830 to the DP port, not the PN port. The PN port will not enumerate the CI830 even if the GSD is installed in the catalog.

FAQ