Characteristics of the auxiliary inputs of the TSX CCY 1128

Characteristics of the encoder inputs

The table below gives the characteristics of the A, B and Z encoder inputs.

Input			RS 422 use	Use at 10… 30 VDC
Logic			Differential inputs	Positive or negative
Nominal values	Voltage		-	24 V
Nominal values	Current		10 mA	15.5 mA
Thresholds	Voltage		< 5.5 V	< 30 V (possible up to 34V, limited to 1hr in 24)
	In state 1	Voltage	> 3 V (1)	> 11 V
	In state 1	Current	> 5.8 mA (1)	> 5 mA
	In state 0	Voltage	< - 3 V	< 5 V
	In state 0	Current	< - 5.8 mA	< 2 mA
Input impedance at nominal voltage			-	1.5 kOhms
Type of input			Resistant	Resistant
Maximum permitted frequency	Incremental encoders		500 kHz multiplied by 1 250 kHz multiplied by 4

(1) The positive or negative differential voltage must be higher then 3 volts, and the current in the positive or negative loop must be higher than 5.8 volts to guarantee:

the inclusion of count pulses up to 500 kHz,
that the line control does not detect errors, irrespective of the frequency.

NOTE: Comparison of the RS 422 standard encoder outputs

An encoder with RS 422 standard outputs can control the inputs of two TSX CCY 1128 modules in parallel. In order to guarantee the necessary voltage levels, the encoder supply voltage must be higher than 4.5 V.