Technical information

Technical Information • SCS-TRUMPET • CPU Expansion Side Card

COM-A/B

The on-board Super-I/O (SIO) on the SCS-TRUMPET provides four asynchronous serial interfaces, one

or two of them optionally available from the front panel (EIA/TIA 232). The other two (TTL-level) are

available for rear I/O via P4 as an option, or can be used across the mezzanine connector FIO by

means of the C32-FIO mezzanine board (12HP front panel assembly).

Due to another (primary) SIO potentially available on the CPU host board, the serial interfaces are not

necessarily dedicated to the COM-1/COM-4 ports of a typical Windows PC. Verify or modify the

accompanying CPU BIOS settings for mapping of physical asynchronous serial I/O ports to the logical

COM port order. Being ignorant of the actual port mapping, the serial port front panel connectors are

marked neutrally as COM-A and COM-B (COM-C and COM-D in addition when using the optional

C32-FIO mezzanine board).

COM-A/B • RS-232

Male D-Sub 9 (261.02.009.23)

1DCD

DSR 6

2RXD

RTS 7

3TXD

CTS 8

4DTR

RI 9

5GND

The COM-A male D-SUB connector is a manufacturing option, exclusive to 2 x USB 2.0 receptacles.

The COM-B male D-SUB connector is exclusive to the dual USB 3.0 stacked jack. Two on-board ESD

protected RS-232E transceivers on the SCS-TRUMPET will allow a bit rate of up to 250kbps via

COM-A/B.

As mentioned, serial ports (TTL level) are also available for rear I/O across P4, as an option. When

using the serial port 1 and 2 for front panel I/O, there is a conflict with the on-board EIA-232

transceivers related to COM-A/B. Hence, in order to avoid signal interference, the on-board

MAX3243E serial transceivers must not be stuffed or disabled, for signal usage of the serial ports 1/2

on a rear I/O transition module. Consider usage of the serial ports 3 and 4 as an alternate to the serial

port 1 and 2 for rear I/O. However, if the C32-FIO mezzanine module is engaged on the

SCS-TRUMPET, the serial ports 3/4 are also in use for additional EIA-232 transceivers and C32-FIO

front panel D-SUB connectors (COM-C, COM-D). If in doubt, please discuss your individual

requirements with sales@ekf.de before ordering.

261.02.009.23