EKF C23-SATA Technical Information page 25

Technical Information C23-SATA • PCIe to SATA RAID Controller Mezzanine Card
For selection of the TR1 operating mode, a five position dual row pin header is provided, named
J-SER. A single jumper selects between the following transfer characteristics:
• Jumper J-SER position 3 must be set for RS-232 operation.
J-TRM2.
• Jumper position 5 is suitable for RS-485 point-to-point connection (full-duplex mode =
sending and receiving data simultaneously across a double twisted pair cable). The TxD
transmitter is permanently enabled.
• Jumper positions 7 and 9 must correspond to the software protocol in use in a bus structured
RS-485 topology (party line, transmitter outputs and receiver inputs connected together using
a single twisted pair cable, half-duplex transmission). Either RTS or DTR can be used for
transmitter control.
In rare cases, a node has to be configured as listener only. Simply remove the jumper from J-SER in
order to permanently disable the RS-485 TxD transmitter.
Please note: Do not stuff more than a single jumper to J-SER. Do not install the jumper to other
positions than shown above.
In addition to J-SER, there may be two jumpers provided for on-board line termination of the RS-485
© EKF
J-SER
240.2.04 © EKF ekf.com
1 3 5 7
Transceiver Mode Controlled by GP40
1 3 1 5 7
RS-232
1 3 5 7 1 7
RS-485 - Transmitter Always Enabled
1 3 5 7 1
RS-485 - Transmitter Enabled with RTS
1 3 5 7
RS-485 - Transmitter Enabled with DTR
-25-
9
9
9
9
9 1
Remove also jumpers J-TRM1 and
ekf.com