Siemens 6ES7157-0AC85-0XA0 Replacement Solution for ET 200S

Product Overview

Siemens 6ES7157-0AC85-0XA0 Replacement Solution for ET 200S: Smooth Transition from Legacy PROFIBUS Systems

The Siemens 6ES7157-0AC85-0XA0 is the IM157 DP/DP Coupler Module for the ET 200S distributed I/O station, designed to bridge two independent PROFIBUS DP networks within a single ET 200S rack. As legacy SIMATIC S5 and early S7-300 installations reach end-of-life, plant engineers and procurement teams are actively seeking a reliable, drop-in replacement that preserves existing wiring infrastructure, maintains PROFIBUS DP communication integrity, and avoids costly line shutdowns. TOPNLMS stocks verified units of the 6ES7157-0AC85-0XA0 ready for immediate dispatch, backed by a 12-month warranty and pre-shipment functional testing.

Whether you are migrating from a SIMATIC S7-300 DP master to a newer S7-1500 architecture, consolidating two PROFIBUS DP segments under a single ET 200S chassis, or simply replacing a failed coupler module to restore production, the 6ES7157-0AC85-0XA0 delivers the electrical and protocol compatibility your system demands. Its 9.6 kbps to 12 Mbps baud rate auto-negotiation ensures it integrates without reconfiguration into existing PROFIBUS DP networks running at any standard speed. The module is a confirmed drop-in replacement for earlier IM157 hardware revisions, requiring only a GSD file update in SIMATIC STEP 7 or TIA Portal — no changes to field wiring, cabinet layout, or user program logic are necessary.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful migration to or around the 6ES7157-0AC85-0XA0 rarely involves a single module in isolation. In practice, plant engineers replacing a failed DP/DP coupler often discover that adjacent components in the same ET 200S station also require attention. The ET 200S power module PM-E 24VDC (6ES7138-4CA01-0AA0) supplies the 24 V DC rail that feeds the IM157 and all downstream I/O modules; verifying its output voltage before commissioning the new coupler prevents nuisance faults during startup. Alongside the power module, digital input modules such as the 4DI DC24V HF (6ES7131-4BD01-0AA0) and digital output modules like the 4DO DC24V/2A HF (6ES7132-4BD02-0AA0) share the same backplane and are frequently refreshed during the same maintenance window, reducing future downtime risk.

On the PROFIBUS DP network side, the integrity of the bus cable and termination resistors is critical to stable communication. Engineers often pair the coupler replacement with a check or swap of PROFIBUS bus connectors (6ES7972-0BB52-0XA0) and, where cable runs exceed 100 m at 1.5 Mbps, a PROFIBUS RS485 Repeater (6ES7972-0AA02-0XA0) to maintain signal quality across both coupled network segments. For systems where the DP master is a CPU 315-2 DP (6ES7315-2AH14-0AB0) or a CPU 317-2 DP (6ES7317-2AK14-0AB0), the GSD file update for the 6ES7157-0AC85-0XA0 is applied directly in SIMATIC STEP 7 HW Config without any change to the user program, making the transition completely transparent to the control logic already running in production.

Where the migration scope extends to the HMI layer, a SIMATIC TP700 Comfort Panel or OP73 Micro connected via MPI or PROFIBUS DP continues to operate without modification, since the DP/DP coupler is transparent to the HMI communication path. For sites upgrading the DP master to a SIMATIC S7-1500 CPU with a CM 1542-5 PROFIBUS communication module (6GK7542-5DX00-0XE0), the 6ES7157-0AC85-0XA0 on the ET 200S side remains fully compatible, preserving the existing field wiring and I/O addressing. Finally, if the control cabinet houses a SITOP PSU100S 24V/10A power supply (6EP1334-2BA20), no derating is required when adding the replacement coupler module, as its current draw falls well within the supply’s available headroom.

Retrofit Guidance FAQ

Q: Can I replace the old IM157 with the 6ES7157-0AC85-0XA0 without modifying field wiring?
A: Yes. The module uses the same TM-IM/IM terminal module and identical 9-pin Sub-D PROFIBUS connectors. No field wiring changes are required. Simply remove the old module, insert the new one, and update the GSD file in your HW Config project.

Q: Do I need to update my STEP 7 or TIA Portal project?
A: You need to import the updated GSD file (SIEM80C5.GSD) and re-download the hardware configuration to the CPU. The user program (OB, FB, FC, DB blocks) does not require modification. TIA Portal users should use the PROFIBUS device catalog to locate the updated device entry.

Q: What PROFIBUS baud rates are supported?
A: The 6ES7157-0AC85-0XA0 auto-detects baud rates from 9.6 kbps to 12 Mbps on both DP interfaces independently. Mixed baud rates on the two coupled networks are supported, which is a key advantage over earlier IM157 hardware revisions.

Q: Is the module compatible with S7-1500 as the DP master?
A: Yes. When using a CM 1542-5 or a CPU with an integrated PROFIBUS DP interface on the S7-1500 side, the 6ES7157-0AC85-0XA0 operates as a standard DP slave on that network segment. The ET 200S station on the second DP network is unaffected.

Q: What physical space does the module occupy in the ET 200S station?
A: The IM157 occupies the IM slot of the ET 200S head station. No additional DIN rail space is consumed beyond the standard IM position. Cabinet layout and mounting remain unchanged.

Q: How do I verify the module is functioning correctly after installation?
A: Check the BF1 and BF2 LEDs (Bus Fault indicators for each DP interface) — both should be off during normal operation. The SF LED (System Fault) should also be off. Use STEP 7 or TIA Portal online diagnostics to confirm the module is recognized and no hardware faults are reported.

Q: Can this module replace a discontinued IM157 from an older ET 200S configuration?
A: Yes. The 6ES7157-0AC85-0XA0 is the current production replacement for all earlier IM157 DP/DP Coupler variants. It is backward-compatible with existing ET 200S racks and terminal modules, making it the recommended spare and upgrade path for discontinued predecessor models.

Warranty Assurance

Every 6ES7157-0AC85-0XA0 unit shipped by TOPNLMS undergoes a pre-shipment inspection that includes visual examination, label and firmware revision verification, and a power-on functional check. Units are packed in anti-static ESD bags with foam cushioning to prevent transit damage.

12-Month Warranty Coverage: TOPNLMS provides a 12-month warranty from the date of shipment. If the module fails under normal operating conditions within the warranty period, we will arrange a replacement unit or issue a refund — your choice. Warranty claims are processed within 3 business days of receiving the returned item.

Shipping & Lead Time: In-stock units are dispatched within 1–2 business days from our Xiamen warehouse. International shipments are sent via DHL Express or FedEx International Priority, with tracking provided at the time of dispatch. Typical transit times are 3–5 business days to Europe and North America.

After-Sales Support: Our technical team is available to assist with GSD file configuration, HW Config integration questions, and on-site commissioning guidance. Contact us at [email protected] or +86 18359293191 for pre-sales technical consultation or post-delivery support.

Procurement Assurance: We issue a commercial invoice, packing list, and certificate of conformity with every shipment. For customers requiring traceability documentation or third-party inspection, please contact us prior to order placement.