GE Hydran 201i, Instruction Manual

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Chapter 9 • Communications and Networking
9-8 Rev. 6, March 2011 Part 17997
When using a modem, each Hydran 201T i can be set to either one of the two following
modes (in the Communication submenu; see Section 4.5.6 on page 4-21):
• Call OnAlarm : In this mode, the H201T i communicates with the Hydran Host software
through a telephone line each time a gas or fail alarm condition is detected (to select this
mode, see Section 9.6.3 on page 9-13).
• AnswerOnly : In this mode, the H201T i remains silent until a host computer running the
Hydran Host software communicates with it.
In the Call OnAlarm mode, the following actions are performed when an alarm is
triggered:
• The H201T i sends the ATDS0 command through the selected communication channel
(RS-232 or supervisory link; see the CommChannel and DefaultChannel parameters
in the Communication submenu).
• The Hayes-compatible modem receiving this command dials the telephone number
previously stored in its register 0; this number is redialed until the connection with the
host computer’s modem is established. Then, no other message is sent; the host computer
has the responsibility to communicate with the H201T
i in alarm.
• The Hydran Host software answers and receives the alarm message.
• The Hydran Host software displays the alarm states and updates its data bank.
• The user must acknowledge the alarm in the Hydran Host software and take the
appropriate measures.
Note: Acknowledging the alarm in the Hydran Host software does not turn off the
illuminated push-button of the Hydran 201Ci-1 Controller.
9.4 COMMUNICATION PROTOCOL
For serial communications, General Electric Canada uses its own protocol. Data is
transmitted in ASCII codes; data clusters being transmitted are verified and, if necessary,
transmitted again.
9.5 LOCAL NETWORK INSTALLATION
Read first the explanations in Section 5.2.4 on page 5-13.