Daikin D-BACS, Design Manual

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250 12.6 Monitoring and Control Restrictions
Interface for use in LONWORKS
®
12.6.3 LON Address Table Restrictions
- The entry numbers in the address tables used to bind the network variables are limited to a maximum of 15. This must
be taken into consideration when using several parameters upon binding.
12.6.4 Suspension of Message Transmission when Receiving Set Node Mode Online
- The Interface for LONWORKS
®
suspends spontaneous message transmission, such as reports of the bound output
network variable changes and heartbeat, as well as responding to the Node Object, for one minute after receiving “Set
Node Mode Online”, a management message. However, it responds to other network management requests such as
“poll” and “fetch”. This function is a mechanism to prevent time out errors because of transmission of messages
spontaneously issued by the Interface for LONWORKS
®
when it comes online due to use of an installation tool such
as the LonMaker during commissioning.
12.6.5 Group Binding Restrictions
- It is impossible to bind one of the LON monitoring node output network variables and more than one input network
variable in the Interface for LONWORKS
®
. For example, setting one of the output networks of the monitoring node at
‘ON’ cannot turn the A/C units in the 10 groups under the LON monitoring node ‘ON’.
This restriction is based on the LON regulations.
12.6.6 Prohibition Time of Commands from LON (central monitoring panel) when Power is
Restored after Power to A/C Units is Cut
- After restoration of electrical power that was cut to A/C units, commands must be sent from the LON (central
monitoring panel) at least 5 or so minutes after the restoration. A/C communications are initialized for approximately 5
minutes upon power restoration and, thus, the A/C units will not receive any commands from the LON during this time
period.
12.6.7 Room Temperature Report
As the indoor fan stops when the operation is in special operation mode such as thermostat off, at rest or defrosting, the
'Room Temperature Report' is affected by the heat exchanger and the sensor may happen to detect the temperature
different from that of the indoor and transmit the signal.
Due to the above mentioned reason, consider the temperature as a rule of thumb. If the system control is to be based on
this temperature (such as changeover of operation mode and changing the set temperature), the manufacturer of the
building management system is kindly requested to carry out on its own responsibility.
12.6.8 Change of Settings
The system is designed to keep the memory of the set conditions even when the air conditioner stops due to a power
failure. Each time when the setting of temperature, ON / OFF, heat / cool mode, or air volume is changed, it is written into
the non-volatile memory. The frequency of writing the setting into the non-volatile memory is limited and if the setting is
frequently written into memory after exceeding the limit, it may cause malfunction.
Therefore, take caution so that the frequency of changing the setting of each indoor unit may not exceed 7000
times / year when changing the setting of temperature, ON / OFF, heat / cool mode, or air volume frequently by
automatic control or the like from the central monitoring panel.