3. External Connection
CNT24-4(PCI)H
35
Connection Method to the External device 2
-TTL-Level Input-
TTL-Level Input Connection
Use the TTL-Level Input for the connection with a rotary encoder or a linear scale TTL-level output
circuit. The maximum input frequency is 1MHz.
For a two-phase input, connect both phase A and phase B. For a single phase input, connect to either
phase A or phase B. If not using the phase Z, this does not need to be connected.
TTL-Level Input Circuit
Board
Internal
Circuits
Ground
Output pin
Remote Device
Plus
Common
Minus
Common
Diode
+5V
Input pin
ALS541
+5V
10k
Ω
External Power Supply
+5VDC
Diode
Figure 3.11. TTL-Level Input Circuit and Connection Example
CAUTION
-
The general input signal uses the same circuit structure.
-
The cable should be 1.5m or less.
-
To prevent malfunction caused by noise, separate the circuit as much as possible from other signal
cables and noise sources.