Siemens has discontinued their 353 SLC controller. The 353 was used in many process applications for many years. It's discontinuation leaves many companies without an alternative.
Don't worry - you don't have to turn to eBay looking for spare parts? There's a better solution - the Yokogawa YS1700 PID loop controller. The YS1700 is a drop-in SLC replacement for the Siemens 353 and will keep you off of eBay.
The Yokogawa YS1000 Series is the ideal choice for many control applications offering extreme reliability and sophisticated control. This product family has bright, easy-to-read displays, multiple I/O points, and powerful loop tuning. For critical applications, the YS1700 employs dual CPUs for maximum reliability and hard-manual control for added protection. The YS1700’s powerful function block programming allows for custom strategies to control many demanding processes such as boilers and steam generators, PH control, dosing control, and many other demanding plant processes.