Fast mode

The Fast mode in Beckhoff EtherCAT Terminals has developed historically and is an operating mode with which EL Terminals, primarily the EL31xx and EL41xx groups (analog input/output terminals), can be operated with a considerably faster conversion time. Hence, an analog input value can be converted more quickly/more often or output via the controller accordingly. This is achieved at the expense of other features, therefore consideration is required.

If an EL Terminal supports this mode, this is indicated in the relevant documentation.

There are two groups of terminals that support the FastMode:

• Prototypes of EL31x2 and EL41x2, with product launch before 2009:
  You can switch the two-channel analog input and output terminals into Fast Mode by switching off the second channel. When operating with a single channel (Fast Mode) the terminal's conversion time is about one third less than it is when operating two channels. You can find the precise figures for the conversion times in single-channel and two-channel operation in the technical data for the each particular terminal.
• EL31xx and EL41xx from year of manufacture 2009
  CoE access can be deactivated in these terminals (if this is possible according to the documentation). All existing channels can convert faster as a result of this.
  In EL31x2 terminals the Fast mode is automatic enabled but disabled for CoE access.

Here is an example for each group.

FastMode by means of channel deactivation

Example 1

You can switch the second input channel on and off on the Process data tab of the EL3101 under PDO assignment with the aid of the check box (see the red arrow).

Example 2

You can switch the second output channel on and off on the Process data tab of the EL4101 under PDO assignment with the aid of the check box (see the red arrow).

FastMode by means of CoE deactivation

To disable CoE support for input terminals, a

must be entered in the StartUp list in the System Manager for the terminal. This deactivates the CoE later in SAFEOP and OP.

FastMode is activated by the entry "0x80nn" in the "Sync mode" object, while "nn" specifies the synchronization mode.

Filter deactivation for input terminals If FastMode is enabled, filter mode (0x80n0:06) must be disabled!

CoE deactivation for output terminals For output terminals the upper entry must be implemented for the object 0x1C32:01.

More generally, the mailbox traffic of this terminal is turned off by this FastMode.

The CoE access can be reactivated by writing the original value or, for example, x00 in the PREOP phase after CoE 0x1C32:01 or 0x1C33:01. See the entries in the synchronization mode overview regarding this.