Honeywell HC900 User And Installation Manual page 50

Use of properly configured managed switch is recommended to mitigate potential cyber-security/DOS
problems. Safety applications must include a properly configured Firewall. See Ethernet Devices/
Considerations on page Error! Bookmark not defined. for suggested settings.
Redundant Networks
Honeywell Matrikon OPC Server supports redundant networks. Up to 10 connections may be distributed in
any combination across the controller's 2 network ports (E1 and E2). PC hosts may include, for example,
HMI supervisory software and/or Designer Software configuration software. Redundant ports may be used
in a simplex mode (non-redundant).
Peer-to-Peer Communication
Peer-to-peer communication enables any given HC900 Controller to request a peer relationship with up to
32 other HC900 Controllers on the same subnet; other controllers can request a peer relationship with the
controller. The total number of peers that a controller can have a relationship with is 32. Peer-to-peer
communication uses the Ethernet Open Connectivity network and employs standard User Datagram
Protocol (UDP) for fast and efficient transfer of information. Peer-to-peer communication is based on fail-
safe and data expiration mechanisms that provide for fault and loading considerations without requiring
reserved network bandwidth allocation. Peer-to-peer is designed to be easy to configure as part of a
device's standard configuration and does not require the distribution of a global database.
With redundant controllers, peer-to-peer communication always stays with the Lead controller.
Implementing peer-to-peer communications involves:
 Interconnecting controllers with Ethernet media and networking devices (cables, switches, etc)
 Configuration (via Designer Software):

Controller configuration, which includes entry of an IP address and a Subnet Mask, and a Controller
Name for each controller. (The Controller Name is used only by the Honeywell proprietary
software for network access between controllers; it should not be confused with a Network Domain
Name or Workgroup Name.)

Peer Data Exchange (PDE) function blocks, which are included in the control strategy (configuration
file). PDE function blocks include PDE Control, PDE Write, and PDE Read. (Refer to the HC900
Process Controller Function Block User Guide for additional information.)

Safety Peer function blocks, which are included in control strategy (configuration file). Safety Peer
function blocks include Safety Peer Monitor, Safety Analog Import and Safety Digital Import.
Applicable for Safety controllers with version 6.300 and above
An illustration of HC900 Controller Peer-to-Peer on a Local Area Network (LAN) is given in Figure 19.
Typically, a Router is used for interconnection to another network (LAN, WAN, or other). However, Peer
controllers must all be on the same subnet.
For additional details, refer to the HC900 Process & Safety Controller Safety Manual.
36 HC900 Process & Safety Controller User and Installation Manual Revision 6
21 April 2017