ONICON System-30 LonWorks BTU - Manual (Page 21)

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System-30 BTU Measurement System LON 05/14 - 0668-2 / 18337
Page 21
4.6.3 Input Network Variables
The System-30-LON BTU Meter receives remote commands to reset totals from the
network using Standard Network Variable Types (SNVTs). The input network variables are
in ASCII format. They are used to zero the flow, energy and auxiliary pulse totals
transmitted in the output variables listed in section 1.7.1.
The ASCII character reset input network variables are described in the table below.
Column 1 contains a brief description of the network variables. Column 2 contains the
network variable names. Column 3 contains the Lon SNVT used for each variable. Column
4 contains the ASCII single characters that must be transmitted to the meter along with a
description of what they indicate.
ASCII RESET INPUT VARIABLES
Description Variable Name SNVT Name Valid Characters*
Reset Energy-1 nviResetBTU1a SNVT_char_ascii
Write an ASCII 1 (49) to reset the
selected total. Once the total has
reset, change the value to back to
ASCII 0 (48).
Reset Volume-1 nviResetVol1a SNVT_char_ascii
Reset Energy-2 nviResetBTU2a SNVT_char_ascii
Reset Volume-2 nnviResetVol2a SNVT_char_ascii
Reset Auxin1 (Di3) nviResetAuxIn1a SNVT_char_ascii
*Systems that are not set to decode ASCII characters will use and display the decimal
equivalent. These values are shown in parentheses.
4.6.4 Node Object Network Variables
The System-30 LON BTU Meter node object utilizes one output network variable and one
input network variable. These are described in the table below.
NODE OBJECT NETWORK VARIABLES
Description Variable Name SNVT Name
Node object control input nviRequest SNVT_obj_request
Node object response output nvoStatus SNVT_obj_status
4.6.4.1 nviRequest
Five input variable requests have been implemented. These are listed in the table
on the next page. Three of the requests are mandatory functions. They are
Normal, Update Mask and Report Mask. The other two are used to reset totals in
the Btu meter. They are Reset and Clear Reset.
The requests can be used on the node object or on selected function blocks. The
tables on the next page describe the requests and the function blocks associated
with totals in the Btu meter.