FP2−CCU | RS232C Port Wiring |
4.1 RS232C Port Signals
4.1RS232C Port Signals
Pin layout
Pin No. | Signal | Mnemonic | Signal direction |
1 | Frame Ground | FG | — |
2 | Send Data | SD | Unit → External device |
3 | Receive Data | RD | Unit ← External device |
4 | Request to Send | RS | Unit → External device |
5 | Clear to Send | CS | Unit ← External device |
6 | (Not used) | — | — |
7 | Signal Ground | SG | — |
8 | Receive Carrier Detect | CD | Unit ← External device |
9 | Equipment Ready | ER | Unit → External device |
9−pin internal |
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FG (Frame Ground)
This is connected to the FG terminal on the power supply unit, along with the connector housing, through the backplane.
SD (Send Data)
This signal is used when data is being sent to a partner device. With the Computer Communication Unit, the SD (green) LED among the operating status LEDs flashes if the data has been sent properly.
RD (Receive Data)
This signal is used when data is being received from a partner device. With the Computer Communication Unit, the RD (green) LED among the operating status LEDs flashes if the data has been received properly.
RS (Request to Send)
This signal requests that data be sent from a partner device. With the Computer Communication Unit, the RS signal is constantly on.
CS (Clear to Send)
This signal goes on when the partner device is ready to receive data.
With the FP2 Computer Communication Unit, input to this terminal is invalid, so no connections are necessary.
SG (Signal Ground)
This signal provides a common reference potential for circuits connected to the Computer Communication Unit and any external devices.
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