Siemens S7-300 Phase-Out: Options for Existing Plants

SIMATIC S7-300 was for many years one of the most widely used PLC families in factories. Siemens has moved the family into product phase-out and positions the S7-1500 as its successor. This does not mean running systems will suddenly stop; but finding spare parts will get harder over time and prices will rise.

Three basic options

1. 1
   1. Build a spare stock

   Keeping spares of the CPU, power supply and most used I/O modules for critical machines is the fastest short- and medium-term safeguard.

2. 2
   2. Repair

   A significant share of failed S7-300 modules can be repaired at component level. Repair keeps production running without changing the system and helps preserve your spare stock.

3. 3
   3. Planned migration (retrofit)

   In the long term the system needs to move to the S7-1500. Doing the migration during a planned shutdown rather than during a breakdown minimises risk and downtime.

Points to watch during migration

• STEP 7 (V5.x) projects can be migrated to TIA Portal; however, code does not always transfer one-to-one to the S7-1500 and needs review and testing.
• Distributed I/O (ET 200), the HMI and the communication structure with drives (PROFIBUS / PROFINET) must be included in the migration plan.
• On-site work can be reduced by keeping wiring and cabinet layout wherever possible.
• A complete backup of the existing program and hardware configuration must be taken before migration.

First steps you can take today

1. Inventory the S7-300 systems in your plant: order numbers and firmware versions.
2. Back up every system's program and store it safely.
3. Rank machines by criticality; plan spare modules for the most critical ones.
4. Spread the migration over your budget and planned shutdown calendar.

Besides supplying and repairing S7-300 modules, ELKAR provides retrofit and PLC programming services for migration to the S7-1500.