1–4
ControlNet System Overview
Publication 17706.5.20 - June 1997
Communication between either a parallel or serial host and the
KFC15/KFCD15 module is carried out using Allen-Bradley’s
proprietary DF1 protocol. DF1 is a full- or half-duplex protocol that
carries messages intact over a link. The protocol delimits messages,
detects and signals errors, retries after errors, and controls message
flow. In a typical network, as discussed in this manual, the host is the
master station and the KFC15/KFCD15 module is the slave. For a
complete description of the DF1 protocol, refer to the Data
Highway/Data Highway Plus/DH-485 Protocol and Command Set
Reference (1770-6.5.16).
Planning for a Parallel Port
The parallel port interface consists of eight, bidirectional data lines
and nine handshaking lines. Consider the following requirements
when planning for a parallel port connection,
•
Data transfers occur in half-duplex mode between the parallel
host and the KFC15/KFCD15 module.
•