Datasheet

Modbus TCP Communication HIMA H41q/H51q ↔

↔↔

↔ Emerson DeltaV

1. Introduction

There is an increasing need for fast and voluminous data transmission between HIMA Safety PESs

and different DCSs. Modbus TCP is a protocol which can fulfil this need. Modbus TCP communication

combines the proven reliability of the Modbus protocol with the flexibility and speed of Ethernet

networks. The well known Modbus Telegrams are coded into TCP packages and can than be

communicated via Ethernet. As transport layer standard off-the-shelf Ethernet equipment like twisted

pair network cables, switches and fiber optic converters can be used with communication speeds of up

to 1 GB/s. In contrast to standard Modbus RTU the Modbus TCP protocol is multi master capable,

meaning that several communication masters can access the same slaves for information.

The Modbus TCP communication protocol was made available to HIMA´s H41q/H51q and Emerson´s

DeltaV system through market introduction of new communication modules in 2005 and 2006

respectively. Modbus TCP support was added to H41q/H51q systems through introduction of the new

ethernet communication module F 8627X. A communication module from third-party supplier Mynah

named Virtual I/O Module (VIM) added Modbus TCP capability to DeltaV. The Mynah VIM achieves

this through simulating four DeltaV serial cards (eight serial cards for redundant layout) which are

virtually mapped to the last I/O slots (61-64 for non-redundant and 57-64 for redundant

communication) of the DeltaV systems eight possible I/O carriers. The way to configure the data

communication and the applicable communication limitations is therefore the same like with standard

DeltaV serial cards.

Figure 1.1 General Network Layout for Modbus TCP Communication

This Application Note should give an overview of the necessary configuration steps for establishing a

Modbus TCP communication between HIMA’s H41q/H51q safety PES and Emerson Process

Management’s DeltaV DCS.

As precondition for applying this Application Note general knowledge of the H41q/H51q PES and

DeltaV DCS as well as configuring with ELOP II and DeltaV Explorer and Control Studio is assumed

(see Recommended Literature [1], [2], [3], [4]).