Networking And Communication Capabilities - GE Hydran 201 i Instruction Manual

Chapter 1 • Introduction
The Hydran Host software performs five basic tasks:
• A continuous, on-line survey of alarm status and basic information from one or several
H201Ti's
• Real-time logging of information from one or several H201Ti's
• Continuous or programmed uploading of historical data (history download) from one or
several H201Ti network(s) with graphic display
• Downloading and uploading of configuration data (H201Ti set-up) to one or several
H201Ti's from/to the host computer
• H201Ti embedded program upgrading of one or several H201Ti's
1.3

NETWORKING AND COMMUNICATION CAPABILITIES

Up to 128 Hydran 201Ti Intelligent Transmitters can be connected in a single network and
monitored and controlled by computer (either locally or remotely through a modem) using
one RS-232 communication port. This is accomplished by connecting groups of one to four
H201Ti's to a Hydran 201Ci-C Controller via an isolated supervisory link, and then
connecting the many H201Ci Controllers via an isolated RS-485 LAN.
Each supervisory link is isolated to a level of 2,000 V RMS, both at the H201Ti end and at
the H201Ci end. Individual transmitters can be wired directly to their group controller if the
total cable length does not exceed 1,200 m (4,000 ft).
The supervisory links and the RS-485 LAN are electrically isolated and all H201Ci's on a
network share a single reference ground. The H201Ci's are networked together in a daisy-
chain fashion. Usually, the H201Ci's are to be found in a well-defined area of a substation
(such as a control building) but the RS-485 LAN can have a total length of 1,200 m
(4,000 ft) if required. For 32 H201Ci's, this gives an average distance of 40 m (120 ft)
between each H201Ci.
Although the RS-485 LAN is electrically separate from the multiple supervisory links, the
entire system forms a single logical network and each of the H201Ti's, up to a maximum
of 128, can be called by the supervisory computer using the Gas Monitor Address of the
transmitter (a user-defined number from 1 to 254 specific to each H201Ti).
The supervisory computer can be indifferently connected to the RS-232 or USB port of any
of the H201Ci's since each H201Ci automatically routes communications to and from its
RS-232 or USB computer port, isolated supervisory link port and isolated RS-485 LAN
1-6 Rev. 6, March 2011 Part 17997