Honeywell 900U02-0100 - Serial Ports; Figure 23 - Controller Serial Ports

38 ControlEdge HC900 Process & Safety Controller User and Installation Manual Revision 10
May 2019
2.8. Serial Ports
RS-232 and RS-485 for legacy systems
Overview
(RS-232 and RS-485 for legacy systems and two galvanically isolated RS-485 ports for new systems)
Figure 23 – Controller Serial Ports
 For Legacy systems, the S1 default setting is RS-232; S2 default setting is RS-485. Each port
can be set to RS-232 or RS-485 (see page 39). For RS-232 cable connections see page 143.
For RS-485 connections see page 160.
 For new systems, either of two ports S1 and S2 can be configured as RS-485. For SIL
applications communication cable shield connection must be made to IO grounding bar
instead of the connector shield connector.
 Ports configurable as ELN (default) or Modbus RTU.
 Controller can act as Modbus master or slave through either port.
 Controller can be slave to masters such as
 On Legacy systems- Operator Interface (1040, 559). Must be on galvanically isolated RS-
485 port S2.
 Honeywell HC Designer PC software
 Third party PC HMI software
 Third party Operator Interface
 Controller can be master to slaves such as
 Any Honeywell Modbus device (e.g., recorders, controllers, flame safety)
 Any non-Honeywell Modbus device.
 Only one master port at a time; can’t have both serial ports as master ports.
 Modbus master ports default to slave ports, ELN protocol when CPUs are in Program mode.
 Baud rates to 115,200