Samsung SSA-P401 - Manual (Page 25)

Problem Action
No communication is available
when the system is in sync with the
PC. 1) Check the communication settings between the PC application and the device.
- Check the board ID (COMM address) and match it with that of the PC application.
- Specify a unique board ID (COMM address) for each of the multiple devices.
- Check the baud rate if it matches with the PC application.
- If you initialize the device, it will be defaulted to 9,600bps.
- Check if the communication port of the PC matches that of the PC application.
- Check the communication settings of the PC application.
Parity Bit : NONE, Data Bit: 8bit, Stop Bit: 1bit
2) Check the connection status of RS-232 and RS-422.
RS-232 RS-422 (Independent Communication)
SSA-P400 PC SSA-P400
RS-232/RS-422
Converter
PC
TX Port RX RX(-) TX(-)
Connected to the
RS-232 cable of the
converter
RX Port TX RX(+) TX(+)
GND GND TX(-) RX(-)
TX(+) RX(+)
Rs-422 (Multi-Unit Communication)
SSA-P400 SSA-P400 RS-232/RS-422 PC
RX(-) RX(-) TX(-)
Connected to the
RS-232 cable of the
converter
RX(+) RX(+) TX(+)
TX(-) TX(-) RX(-)
TX(+) TX(+) RX(+)
For RS-422 communications, install a termination resistor at the point where the
system is connected to the RS-422/RS-232 converter of the PC.
(Install a 120Ω termination resistor between the RX+ and the RX- terminals on the
device side, another 120Ω between the TX+ and the TX- terminals; the same
should be done to the converter. If you are not sure about the wiring, contact the
customer service for your help.)
If the problem persists after you followed the instructions above, this may be caused
by the defective of an internal circuit. Contact the customer service.
¼ If no communication is established after you tried to do so with multiple
devices, pick just one device and connect it to the RS-232/RS-422
converter, and to the PC. Then, check if there is any communication
available.
English 25