Key Technical Specifications

Parameter	Specification
Manufacturer	ABB
Model	TP853
Order Number	3BSE018126R1
Product Type	PROFIBUS-DP Baseplate for S800 I/O
Controller Interface	PROFIBUS-DP
I/O Compatibility	ABB S800 I/O modules (standard and S800L mixed use)
Internal Bus	ModuleBus distribution to S800 MTUs
Max I/O Modules per Station	Up to 12 standard S800 modules; up to 24 with fiber ModuleBus extension
Mounting	DIN-rail mounted field base
Environmental Rating	S800 family generally G3 conformal coating; TP853-specific rating to be confirmed from OEM manual
Typical Ambient Range	S800 I/O commonly 0 to 55 °C; verify TP853-specific limit in the OEM datasheet
Supply	24 VDC S800 station supply (exact TP853 terminal/voltage limits to be confirmed from OEM manual)

 

Product Introduction

If you have ever walked into a remote instrument shelter and found an S800 rack hanging off a PROFIBUS-DP segment, there is a decent chance the TP853 was sitting at the left end of that row. It is not an I/O module. It is not a power supply. It is the field baseplate that turns a group of S800 MTUs into a recognized PROFIBUS-DP station.The reason this part still shows up in replacement requests is simple: the S800 platform was deployed everywhere from pulp mills to offshore platforms, and the TP853 handled the dirty work of PROFIBUS termination, node addressing, and ModuleBus distribution. It does not need flashy specs. It needs to hold address settings, survive humidity, and keep the DP segment stable when the cabinet door has been left open one too many times.

Quality SOP & Tech Pitfalls

The Lab Report (SOP)

1. Visual inspection: verify label “TP853 / 3BSE018126R1,” check DIN-rail latch, PROFIBUS connector pins, and ModuleBus contacts.
2. Counterfeit/revision check: compare ABB label format, order number, and mechanical connector style.
3. Live test: mount on a compatible S800 test rack with a 24 VDC station supply and verify PROFIBUS-DP node recognition.
4. ModuleBus check: confirm downstream S800 MTUs receive proper bus communication and addressing.
5. PROFIBUS termination test: verify end-of-segment termination behavior per site configuration.
6. Documentation: record serial number, revision, test results; ship in anti-static packaging.

The Engineer’s Warning (Pitfalls)

• Do not confuse TP853 with a TU8xx MTU. TP853 is the PROFIBUS-DP base for the station. TU810/TU811/TU843 are module terminal units for wiring I/O signals. Swapping one for the other will not work.
• PROFIBUS address and termination matter more than the module itself. A wrong node address or missing termination resistor will take down the entire segment, not just one card.
• Corrosion kills field bases faster than CPUs. S800 modules often carry G3 coating, but the baseplate connectors, DIN-rail contacts, and PROFIBUS pins still corrode in wet shelters. Inspect the pins before blaming the PLC program.
• Third-party dimension/voltage claims are unreliable. Treat any datasheet that does not reference an ABB OEM document with caution.

 

Installation & Configuration Guide

1. Pre-Installation

• ⚠️ De-energize the S800 station and verify the 24 VDC supply is isolated.
• ⚠️ Photograph the existing PROFIBUS address switches, termination settings, cable orientation, and ModuleBus links.
• Confirm the PROFIBUS node address matches the control system configuration.

2. Removal

• Disconnect the PROFIBUS cable first.
• Remove downstream S800 MTUs only if required for access.
• Release the DIN-rail latch and remove the baseplate carefully.

3. Installation

• Copy the PROFIBUS address and termination settings from the old unit before powering up.
• Seat the TP853 firmly on the DIN rail.
• Reconnect ModuleBus links to the first S800 MTU.
• Reconnect the PROFIBUS cable with correct polarity and shielding.

4. Power-On & Testing

• Apply 24 VDC station power.
• Verify the PROFIBUS-DP node comes online in the master configuration.
• Check that all downstream S800 modules are recognized.
• Perform a forced I/O test on at least one channel per module to confirm ModuleBus communication.

Compatible Replacement Models

Replacement	Compatibility	Notes
ABB TP853 3BSE018126R1	✅ Drop-in	Same model and order number. Lowest risk.
ABB TP853 (other revision)	⚠️ Verify	May work if mechanical and firmware behavior match. Confirm with OEM manual.
ABB CI830 PROFIBUS-DP interface	⚠️ System-level alternative	CI830 is a PROFIBUS-DP communication interface for S800 stations; not a direct TP853 baseplate swap.
CI840 / CI840-based PROFIBUS solution	❌ Not a direct swap	Different hardware family and station architecture.
Generic PROFIBUS coupler	❌ Not recommended	S800 ModuleBus addressing and mechanical integration will not match.

 

Frequently Asked Questions (FAQ)

Q1: Is TP853 an I/O module?
No. It is a PROFIBUS-DP baseplate for an S800 I/O station. The actual analog, digital, or HART channels come from the S800 modules mounted downstream.Q2: Can I replace TP853 with a TU811 or TU843?
No. TU8xx units are module terminal bases for wiring I/O signals. TP853 provides the PROFIBUS-DP interface and station base function.Q3: What PROFIBUS speed does it support?
That depends on the S800 station configuration, the master settings, and cable length. Do not guess; check the S800 PROFIBUS documentation for the installed firmware and network design.Q4: Is it still in production?
It is a long-life legacy product. New original stock from ABB may be limited. Most available units are New Surplus or tested surplus. Always request label photos.Q5: Can I hot-swap it?
Not as a routine maintenance action. The S800 family supports module replacement in many cases, but replacing the PROFIBUS baseplate usually interrupts the station. Plan a controlled outage.Q6: What fails most often on these?
Bad PROFIBUS connectors, corroded ModuleBus contacts, wrong node address, or missing termination. The electronics usually outlast the mechanical contacts in humid cabinets.Q7: How do I confirm I am buying the right part?
Match both “TP853” and “3BSE018126R1” on the label. Then verify the PROFIBUS connector style and revision against your existing unit.