Use the Change Processor Function

you can use the change processor function to alter incoming messages based on specific parameters and requirements you can assign new values, update existing information, or restructure data for better organization this guide explains the different operational modes in the change processor function using a real world scenario with tags and devices in litmus edge understanding different modes in change processor function the change processor function offers several operational modes, each tailored for specific types of modifications set mode this mode lets you directly replace a specified field's value when the change mode is set to "set," the input value overwrites the existing content in the designated message field change mode this mode enables complex string manipulations it operates differently depending on the data type of the input field for string or json fields, it will search for all occurrences of the specified value within the field and replace them with the replace value both value and replace value will be treated as strings during this operation for other data types, the processor looks for an exact match between the value and the field if a match is found, the field content will be replaced with the replace value delete mode this mode is used to remove specified values from the input field entirely when set to "delete," it eliminates the designated content move mode this mode takes the modified content from one field and relocates it to another field within the same message user scenario review the following scenario for the change processor function then, you will simulate plc data and modify incoming messages using different modes of change processor function in a manufacturing facility, a sensor sends messages \['heat', 'humidity', 'temperature'] with machine status reports a technician can use the change processor function to optimize this data in the following way in set mode , they update the devicename field from "test device" to "validation device" during production runs in change mode , they replace all occurrences of "heat" with "heating problem" in maintenance reports in delete mode , they remove outdated deviceid field that no longer apply in move mode , they transfer the updated values from the value field to a new updated values field step 1 add a device follow the steps to connect a device docid\ ish7bqhzxswtdx8vbnszb and configure the following parameters device type simulator driver name generator enable alias topics select the checkbox step 2 add tags after connecting the device, add the following tag see add tags docid\ xgwokqbtpevii7or82ll0 to learn more only one tag will be used for simulating the different switch processor outputs mentioned above tag 1 tt1 name select s random value generator value type select string polling interval enter 5 tag name enter tt1 step 3 create analytics flows you can now create the analytics flows using data from the device and tag you previously created choose the appropriate step from 3a, 3b, 3c, or 3d based on the desired mode of the change processor function to create an analytics flow with the change processor function navigate to analytics on the analytics canvas, click add processor the create a processor dialog box displays select datahub subscribe in the topic field, click the search icon, select the device you previously created, and then select the alias topic for the tt1 tag click save step 3a configure set mode click add processor again and select change the following information defines this function mode select set from the drop down menu input field enter devicename input value type select string from the drop down menu input value enter test validation click save connect the datahub subscribe processor (tag tt1) to the change processor with a wire and use the events connection on the analytics canvas, click save the configured analytics flows should look like the following step 3b configure change mode click add processor again and select change the following information defines this function mode select change from the drop down menu input field enter value input value type select string from the drop down menu input value enter heat replace with value type select string from the drop down menu replace with value enter heating problem click save connect the datahub subscribe processor (tag tt1 ) to the change processor with a wire and use the events connection on the analytics canvas, click save the configured analytics flows should look like the following step 3c configure delete mode click add processor again and select change the following information defines this function mode select delete from the drop down menu input field enter deviceid input value type select unit from the drop down menu click save connect the datahub subscribe processor (tag tt1 ) to the change processor with a wire and use the events connection on the analytics canvas, click save the configured analytics flows should look like the following step 3d configure move mode click add processor again and select change the following information defines this function mode select move from the drop down menu input field enter value input value type select string from the drop down menu move to field enter updated value click save connect the datahub subscribe processor (tag tt1 ) to the change processor with a wire and use the events connection on the analytics canvas, click save the configured analytics flows should look like the following step 4 view output of processor click the view icon in the change processor to view the output values view set mode output the set mode assigns the test validation string to the devicename field view change mode output the change mode switches the occurrence of heat string in the value field with the heating problem view delete mode output the delete mode removes the deviceid field from the message view move mode output the move mode transferred the value field to the new updated values field in the message