ST2883 Series Operation Manual Chapter 9 Handler interface
9-4
A simplified diagram of the output signals is shown in Figure 9-1. * is the default jumper setting when shipped
from factory. That is to say, the default jumper setting is to use external voltage source.
Refer to the next section Jumper Setup.
9.2.2 Isolated input
The /START signal (pin 7) and the /STOP signal (pin 8) are connected to the cathode of the LED in an opto-coupler.
ST2883 series is triggered on the rising edge of the /START pulse and stopped on the rising edge of the /STOP
pulse. The anode of the LED can be connected to the in5V, or an external voltage source EXV (the same
external voltage source used for output signal).
Figure 9-2 Simplified diagram of the input signal
In figure 9-2, the default jumper setting is to use external voltage source. Actually, the input signals and the output
signals use the external voltage source together. The Current-limit resistor is used to limit the current and the
default resistor is only suitable for external voltage source range from 5V to 8V. If the external voltage source is
higher than 8V, you should replace the Current–limit resistor to avoid damaging circuit components. Current-limit
resistor R705 and R706 should be both replaced. The detailed replacement information about Current-limit resistor
is listed in table 9-2.
Current-limit resistor
Range of external voltage source
680
Ω
5V to 8V
1.2K
Ω
8V to 15V
2.2K
Ω
15V
to
24V
Table 9-2 Current-limit resistor for different voltage
