Introduction
Incremental encoder interface, RS422, TTL, 1 MHz
The EL5101 EtherCAT Terminal is an interface for direct connection of incremental encoders with differential inputs (RS422) or TTL single ended signals. Input frequencies up to 1 MHz can be evaluated. The measurement of period and frequency with a resolution of 100 ns is possible. The EL5101 can also be used as bidirectional counter on channel A; channel B specifies the count direction.
Two additional 24 V digital inputs are available for storing, blocking and setting the counter status. The gate input allows the locking of the counter, alternatively with a high or low level. The latch input is similarly configurable and evaluates high or low levels.
Incremental encoders with alarm output can be connected at the negative switching status input of the interface. The 5 V and 24 V supply of the encoder can be provided directly via the terminal connection points.
In normal operating mode a 16-bit counter and a 16-bit latch for the zero pulse can be read, set or enabled.
The enhanced operating mode is available through the further development of the EL5101 (from firmware 14 / hardware 09). It can be parameterized in the TwinCAT System Manager, depending on the hardware used. Older EL5101 devices do not support this enhanced operating mode (see Table below)!
Operating modes EL5101 | from FW/HW | ESI | Functional description |
|---|---|---|---|
normal operating mode | 03/05 | from EL5101-0000-0000 | All basic functions as described above |
enhanced operating mode | 14/09 | from EL5101-0000-1018 | Changes to the normal operating mode
|
In enhanced operating mode a switchable 16/32-bit counter and a 32-bit latch for the zero pulse can be read, set or enabled.
The EL5101 supports distributed clocks in the enhanced operating mode, i.e. the input data can be recorded synchronously with other data that are also linked to Distributed Clock slaves. The accuracy across the system is < 100 ns.
The documentation is divided in the chapter "EL5101 - Commissioning" into the handling of the two operating modes. During commissioning it must be decided which operating mode is to be used.