SystemCommand Function Block
The System Command function block is used to override the following wall module to system commands. The wall module sends a command to the AHU or VAV system.
Following are the five system command/states available in the wallmodule:
Off / Heat (Heat only)
Off / Cool (Cool only)
Off / Heat / Cool (No Auto changeover)
Off / Auto / Heat / Cool (Auto changeover)
Off / Auto / Heat / Cool / Emergency Heat (Heat Pump)
It is also possible to override the output from this block by making change in the in field.
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Figure 2: SystemCommand Property Sheet |
Inputs
Input Name |
Description |
In |
To provide the System Command from the controller to the Wall module. Following are the five system command options available in the wallmodule:
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Table 1: Inputs of SystemCommand Function
Output
Output Name |
Description |
Out |
To provide the Final System Command from wall module to the controller. Following are the five system command options available in the wallmodule:
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Table 2: Output of SystemCommand Function
Parameters
Parameter Name |
Description |
sylkDevice |
This option is used to select the sylk device from the dropdown menu which needs to be linked with the System command. Default is None |
Master Sync Enabled |
Master Sync Enabled is true, this property is synchronized between master and slaves in case a master sync operation is performed. The source device setting is synchronized to a target device during a master sync operation. If the source device has set the flag to false, then this parameter will not be synchronized to all target devices. |
Status |
Read-only point. Shows the status of the parameter. (alarm, fault, overridden, disabled, down, stale, null, unackedAlarm).
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faultCause |
Read-only point. Indicates the reason why a system object (network, device, component, extension, etc.) is not working properly (in fault). This property is empty unless a fault exists. |
sendInterval (seconds) |
Send interval is the time between the end of a timeout period or completion of a network request, and the next request for data on the network. Default is 60 Seconds. |
enableFD |
enableFD - Fail Detect is the time until the Sylk controller is notified of a failure on this point. Yes: If the parameter has not received an update from the IRM network source in the fail detect time, then an alarm is generated, and the present Value is set to Invalid. It is envisioned that most (all) input and input/output parameters will be fail detect so that Sylk controller does not display stale or misleading data. Note: Fail detect time depends on the update rate configured. No: False means the object retains the last value that was written to it until a IRM network source changes. Fail Detect is disabled in the System Command function block and it is not configurable by the user. Update Rate: The rate at which inputs are sent to the network. |
systemCommands |
Allows to select the modes of the command from the wall module to the system. Following are the five valid system command options available: Off / Heat (Heat only) Off / Cool (Cool only) Off / Heat / Cool (No Auto changeover) Off / Auto / Heat / Cool (Auto changeover) Off / Auto / Heat / Cool / Emergency Heat (Heat Pump) Default Value is Off / Heat (Heat only). |
defultSystemCommands |
Allows to set the default value for the system command options. Following are the five default system command options available:
Default Value is Off |
systemCommandValues |
System command values displays the various command values depending on the valid system commands selected, the respective values are enabled. Invalid values are disabled (depending on the system configuration options selected). Users will be able to switch to Off, Auto, Heat, Cool, Emergency Heat modes. Off =255 Auto=0 Heat=2 Cool=1 Emergency Heat=3 Emergency Heat, also known as auxiliary heat, is the second stage of heat that your thermostat runs on when the temperature is too cold for your heat pump to extract heat from the outside. Emergency Heat is triggered when it is 35°F and below outside. Emergency heat should really be switched on by the users in emergency situations when something happens to the first stage heat source heat pump. Numeric: 32-Bit Integer value 0, 1, 3, 255. Default: Null. |
SetAsNetworksetpoint |
This option to connect the System command block with the Network input/set point and the Network output point. If the option is not selected, the System command block can relate to the Network output point, but not with the Network input/ set point. Note:Set as Network Setpoint is disabled by default. The default value is No. By clicking YES or NO, you can enable or disable this option. Note:Set as Network Setpoint option is available only for the TR71/TR75/TR120 model. |
Out Save |
Master Sync Enabled : If you set it to "true" the last output will be set as output for one cycle after the controller restarts. The application can use it to return to the same state before the controller restart. Out: To enable or disable the Out feature. |
Table 3: Parameters of SystemCommand Function
Refer to General Description for general information about IRM N4 Function Blocks.
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