PLC System - PLC Programming & Automation

Download without reinitialization in TIA Portal: keeping values after an interface change

September 14, 2026 by PLC System

Instance DB of FB_Recipe drawn as three bars: 84 bytes of statics with a 100 byte memory reserve and a 100 byte retentive reserve where values stay live, the same DB after one Bool is added leaving 99 bytes of reserve with values kept, and the same change with no reserve where the DB is rebuilt from start values and the values are lost

Add one Static to an FB and every setpoint in the instance DB goes to zero. How the memory reserve prevents it, how to size it, and how to recover.

TIA Portal HSP missing: getting a new device into the hardware catalog

September 14, 2026 by PLC System

Hardware catalog tree for the CPU 1214C DC/DC/DC with article number 6ES7 214-1AG40-0XB0, showing versions V4.0 to V4.5 with V4.6 missing before the support package and V4.6 present after it, plus the five installation steps

The CPU says V4.6 and the hardware catalog stops at V4.5. What a hardware support package does, how to install one offline, and when you need a newer TIA.

S7-1200 firmware mismatch: why the download stops and how to fix it

September 14, 2026 by PLC System

Two cases side by side: a project configured V4.4 against a CPU running V2.2 where the download is refused, and a project configured V4.5 against a CPU running V4.6 where the download runs, with the three remedies listed as change device version, change device and firmware update

TIA Portal refuses the load because the CPU firmware is lower than the configured version. Read the real numbers, then pick the fix.