Trane Engineered Smoke Control System, Application Manual

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Chapter 8 Network variable bindings
122 BAS-APG001-EN
Tracer MP580/581 bindings
This section discusses which network variables will be necessary to
achieve UUKL time performance requirements. Only “generic” network
variables, which are neither Space Comfort Controller (SCC) or Discharge
Air Controller (DAC), are necessary. Use of generic variables does not
affect either BCU auto-bound network variables or SCC or DAC based
network variables.
Receiving data
A network variable input (nvi) receives data from other devices on the
LonTalk network. The generic network variable inputs, nviSwitch and
nviPercent, that are commonly used in Tracer MP580/581 bindings are
shown in Table 29.
Sending data
A network variable output (nvo) send s data to other devices on the Lon-
Talk network. The generic network variable outputs, nvoSwitch and nvo-
Percent, that are commonly used in Tracer MP580/581 bindings are
shown in Table 30.
Heartbeated network variables
All necessary information can be sent using nvoSwitch (SNVT_switch)
and nvoPercent (SNVT_lev_percent), which are “heartbeated” variables.
All necessary information can be received using nviSwitch
(SNVT_switch) and nviPercent (SNVT_lev_percent). Heartbeated
variables are a means of indicating freshness of information and/or
quality of the communication link. For more information regarding
heartbeating, see “Understanding bindings” on page 130.
Table 29. Tracer MP580/581 generic network variable inputs
Variable name SNVT Data type Description
nviSwitch01 …
nviSwitch40
SNVT_switch Binary Bind to these 40 network variable inputs to communi-
cate binary values to the device.
nviPercent01 …
nviPercent20
SNVT_lev_percent Analog Bind to these 20 network variable inputs to communi-
cate levels in percent to the device. The valid range is
from –163.84% to 163.83% with a resolution of 0.005%.
Table 30. Tracer MP580/581 generic network variable outputs
Variable name SNVT Data type Description
nvoSwitch01 …
nvoSwitch40
SNVT_switch Binary These 40 network variable outputs communicate binary
values to other devices.
nvoPercent01 …
nvoPercent20
SNVT_lev_percent Analog These 20 network variable outputs communicate levels
in percent to other devices. The valid range is from –
163.84% to 163.83% with a resolution of 0.005%.