Execution_signal example

The execution_signal parameter returns information about the specific signal that triggered execution. If there are multiple possible source signals, it identifies the one that actually initiated the execution. In this example, Modbus RTU protocol is used. Configuration of devices:

Execution_signal should always be "signal" when execution_signal is used. PORT2 is used to connect IOMod 8DI8DO to WCC Lite via RS485. IOMod signals configuration in this case:

In this case IOMod's input signals are used, but also other signals can be used depending on needs. Map the signals as shown below:

First lua signal is executing first input signal, while second lua signal is executing second input signal. Results signal is used to store information about executed signal.

A Lua script can be written in various ways using the execution_signal parameter. However, in this example, a simple Lua script is used to retrieve the signal_alias of the executing signal by accessing execution_signal.tag.signal_alias:

local DI = execution_signal.tag.signal_alias

if DI == "DI1_lua" then
    publish(signals.results, 1)
elseif DI == "DI2_lua" then
    publish(signals.results, 2)
end

This is just one example of execution_signal usage. It can retrieve different information about executing signal using:

execution_signal.tag.device_alias - retrieves device_alias
execution_signal.tag.signal_alias - retrieves signal_alias
execution_signal.value.value - retrieves value of executing signal (for example, 1 or 0)
execution_signal.value.time - retrieves system time in milliseconds (UNIX timestamp)
execution_signal.value.attributes - retrieves attributes (for example, iv, nt, sb)

Upload the configuration to WCC Lite (it should upload without any errors):