SERIAL CODE OPERATED SWITCH S-COS/2
11
3.3 Jumpers
J1 — B
REAKS
When jumper J1 is installed, the S-COS/2 will pass breaks. If jumper J1 is not installed, the S-COS/2 will
not pass breaks.
The S-COS/2 generates a break signal as follows: When the master or slave port UART receives a break,
the UART raises pin 14 to a logical 1 (this represents a framing error to the UART). The UART thinks it
has received a character with an invalid stop bit. The raising of the framing-error pin starts the
multivibrator timing circuit that sends a constant space signal for approximately 257 milliseconds to the
connected output port. This duration represents a break.
Once the break condition has occured, multiple breaks cannot be sent, because the framing-error pin
on the UART cannot be reset, and the UART does not know whether the next character received is valid
data or not. To reset the framing-error pin on the UART, put the S-COS/2 into Switch Time Mode (see
Section 4.1
). Then reconnect the other port or power off and on.
Figure 4. J2 Jumper Settings.
J2 — M
ODE
D
EFAULT
S
ETTING
Jumper J2 determines the default mode when the S-COS/2 is powered up or reset. See Figure 4 for the
available settings and results.
3.4 Installation Procedure
1. Remove the cover from the S-COS/2.
2. Set the switches for your application as described in
Section 3.2
.
3. Replace the cover of the S-COS/2.
4. Connect the serial devices to the terminals on the rear of the S-COS/2.
5. Plug the power cord into the AC wall outlet.
6. Apply power to the connected devices.
The S-COS/2 is now ready for operation.
POWER UP TO
SWITCH TIME MODE
POWER UP
TO PORT A
POWER UP
TO PORT B
Summary of Contents for S-COS/2
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