The S7-300 CPU is the heart of the rack, and a failed one stops production. A wrong replacement wastes days, so check these points before you order.
1. The exact order number
Read the full 6ES7 number from the front label. Similar CPUs can differ in memory, interfaces or technology functions.
2. The firmware version
Match the firmware shown in your project or on the module. If it differs, check the compatibility notes before commissioning.
3. Memory card
Some CPUs store the program on a micro memory card. Keep the card from the old CPU and transfer it, or restore from your backup.
4. Interfaces
Confirm whether you need MPI/PROFIBUS, PROFINET or both.
Examples from our range
Browse the full S7-300 range. If your CPU is not listed, send us the order number and we will source it.