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Introducing the 1779KFM Interface
Chapter 2
24
Figure 2.3
A Computer Communicating with Other Nodes through a 1779KFM Interface
Synchronous
RS422/449
Compatible
Computer
Other Nodes
of the
Data Highway II
Communication
Link
PowerSupply
Board
Media
Access
Board
Host
Board
Host Device
1779KFM Interface
The 1779-KFM interface is compatible only with host devices that have
the following attributes:
The host device must provide HDLC link-layer protocol.
The host device must communicate through a port compatible with both
the RS-422 and RS-449 standards.
The host device must provide synchronization signals as the data
terminal equipment (DTE) device on the link. The 1779-KFM is the
data circuit-terminating equipment (DCE) device.
To communicate with the 1779-KFM interface in a Native-mode
message set, the host device must be a programmable device, such as a
computer.
The 1779-KFM interface communicates through connectors on its front
surface (Figure 2.4).
The RS-449 CHANNEL connector provides cable connection to the host
computer.
The DATA HWY II jack provides dropline cable connection to a tap on a
Data Highway II link. A redundant 1779-KFMR interface has a second
DATA HWY II jack for a redundant set of cabling for the link.
Your Data Highway II cable redundant interface module
(Cat. Nos. 1779-KFLR, -KFMR, -KP2R, -KP3R) has a connector on the
front panel labeled DHII AUX ACCESS. This connector is for future use.
Do not connect any cable to this connector.
Compatible Host Devices
Communication Connections