The FM 355 has 4 separate closed-loop control channels. The controllers display the following features:

• Standard control structures (depending on the control structure selected, a number of different types of control may be interconnected in a single structure):
  • Fixed setpoint control,
  • Cascade control,
  • Ratio control,
  • 3-component control.
• Choice of modes:
  Automatic, manual, safety mode, follow-up mode and backup mode.
• Sampling time (depending on the resolution of the analog inputs and the compensation input):
  • For 12 bits:20 ms to 100 ms.
  • For 14 bits: 100 ms to 500 ms (depending on the number of enabled analog inputs)
• 2 control algorithms
  Self-optimizing temperature algorithm (see below), PID algorithm;
• User-friendly controller optimization:
  The self-optimization function for the temperature algorithm is stored on the module and can be automatically activated in the case of setpoint changes of more than 12 %; the PID control algorithm is optimized using the parameterization screen forms in the configuring package
• Backup mode:
  In the event of CPU failure or CPU Stop, the controller can continue to operate independently. The "backup mode" function is used to set a parameterizable safety setpoint or a parameterizable safety control variable.
• Disturbance variable input:
  the analog inputs can be used for feedforward compensation in addition to actual value acquisition, if desired.

New:

• Wider range of applications thanks to changes in function blocks.
  New function blocks are widening the possible applications for the module. The most important changes are:
  • All Fuzzy temperature controller parameters can be read out and programmed
  • More module parameters can be modified online
  • Comparison of data between the FM and instance DB
  • Significantly faster operation thanks to communication via I/O accesses instead of via SFC RD_REC and WR_REC
• Manual/Automatic changeover
  • Manual/automatic changeover stepless or with a step change, as required
• Higher measurement range resolution for Pt 100 sensors.
  The following measurement ranges can be parameterized:
  • -200 to +129°C or -328 to +264°F
  • -200 to + 556°C or -328 to +1032°F
  • -200 to +850°C or -328 to +1562°F
• Testing functions;
  Enhanced test functions support:
  • Reading of analog and digital inputs
  • Forcing of simulated values for analog and digital inputs
  • Reading of channel-specific parameters
• Firmware update
  • Fast and easy upgrading to the current firmware version via the Internet with the help of the parameterization software

Temperature controller with integrated self-setting

The temperature controller with integrated self-setting is suitable for controlled systems where the entire process has approximately the same temperature when the setpoint is reached, as is the case in water bath controls, steam boiler controls or injection molding machines.

The procedure is unsuitable for controlled systems where the temperature in a significant portion of the process still varies significantly after the setpoint has been reached, as is the case in furnace controls where the air heats up and the temperature is measured. When the air temperature has reached the setpoint, the furnace and its contents can still be cold.

Parameterization

A configuring package is supplied with the FM 355 that contains all the parameterization screen forms required for parameter initialization and startup.

Detailed online Help is available for all screen form screen forms. The parameterization screen forms are called up from STEP 7 following installation.