Differential Output Circuit - HikRobot MV-CL042-91CM User Manual

receiver and the bus should be as short as possible. The bus must have a 120 Ω terminal
resistance.
When the camera is the last receiver on the bus structure, the camera's terminal resistance needs
to be enabled, and the rest camera's terminal resistance need to be disabled. Multiple terminal
resistance should not be enabled on the bus structure, which will reduce signal reliability and may
cause damage to the RS-422 device.
 RS-644 Standard Input
If the differential input adopts RS-644 standard signal, the input terminal must enable 120 Ω
terminal resistance.
 TTL&LVTTL Standard Input
If the differential input adopts TTL&LVTTL standard signal, the input terminal's 120 Ω terminal
resistance must be disabled, and its input electrical feature requirement is shown below.
Voltage
0 V to 1 V
1 V to 3 V
3.3 V to 24 V

9.2.2 Differential Output Circuit

The internal circuit of differential output signals in I/O signals is shown below.
The RS-422 standard and RS-644 standard are applied to the differential output.
 RS-422 Standard Output
In order to make sure the normal operation of output circuit, it is required to connect camera's
ground signal with external ground signal. The output interface can be connected to the RS-422
bus structure as a main dispenser.
Camera Link Line Scan Camera
Table 9-1 Electrical Feature Requirement of TTL&LVTTL
Description
Level low
Unstable voltage, and it is not recommended to use it.
Level high
Figure 9-2 Internal Circuit of Differential output
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