Appendix J. Ethernet Data Interface Setup; Configuring The Modem To Use The Ethernet Data Interface (Optional; Ethernet Flow Control - Comtech EF Data DMD50 Installation And Operation Manual

Appendix J. Ethernet Data Interface
J.1

Configuring the modem to use the Ethernet Data Interface (Optional)

When the optional Ethernet Data Interface Card is installed, all of the Ethernet related menus
become available and can be used to control the interface as follows:
Under the Interface Menu:
Under the Tx Setup Menu:
Set the Tx Clock Polarity to Normal.
Under the Interface Menu:
Under the Rx Setup Menu:
When Ethernet Data Interface is selected, the Tx Clock Source will default to SCTE and the Clock
Polarity will default to Normal. In addition, the Buffer Clock will default to RxSat and the Buffer
Clock Polarity will default to Normal.
J.1.1 Ethernet Flow Control
When disabled, if a packet is received for transmission and no packet buffer space is available,
the incoming packet is discarded.
When enabled, flow control is used to throttle the transmission station in order to avoid
overrunning the transmit buffers, which would in turn cause packets to be dropped. The throttling
mechanism used depends upon the interface and whether it is half-duplex or full duplex.
MN-DMD50 - Revision 3
Set the Terrestrial Interface to Ethernet.
Set the Ethernet Flow Control as desired (refer to Section 4.8.1 for details).
Set the Ethernet Daisy Chain as desired (refer to Section 4.8.2 for details).
Set the Ethernet QOS Type as desired (refer to Section 4.8.3 for details).
Set the Ethernet QOS Queue as desired (refer to Section 4.8.4 for details).
Set the Tx Clock to SCTE.
Set the Terrestrial Interface to Ethernet.
Set the Buffer Size to Zero.
Set the Buffer Clock to Rx Sat.
Set the Buffer Clock Polarity to Normal.
Setup
J–1