Memotec CX900e, Hardware Reference Manual, Page: 56 / 200

CX900e Hardware Reference Manual
5-4
3006M100-002
and at the following asynchronous internal clock speeds:
• 134 bps - 128 Kbps
5.1.3 DTE/DCE Interface Configuration
The V.24 Serial I/O Card’s port can be configured either as a DTE or a DCE
device. The DCE/DTE strapping has been silk-screened on the I/O card to aid in
configuration.
DCE
When configured as a DCE device, the port transmits DCD, DSR and CTS and the
synchronous clock signals TXC and RXC. The port must receive DTR and RTS
from the attached DTE. Terminals, printers, controllers and hosts are always DTE
devices.
DTE
When configured as a DTE device, the port transmits DTR, RTS and ETXC and
receives DCD, DSR and CTS and the synchronous clock signals EXTC and RXC
from the attached DCE.
Two jumper banks socketed at U10 and U11 provide DTE/DCE configuration.
Permanent metal bands on the top surface of the jumper banks strap signals
according to DCE/DTE requirements. The orientation of these jumper banks
determines whether the port will be DTE or DCE. Rotating each jumper 180°
changes the port from one kind of device to the other, as illustrated below.
Figure 5-3 V.24 DTE/DCE Configuration Jumpers