Reference Design Content
Modbus is an application-level protocol which defines a set of functions used for interaction between a master [client] device, such as an HMI or PAC, and a slave [server] device, like a PLC, gateway, or sensor. Every interaction between master and slave is a request-response interaction. That is, the master initiates all communication and is responsible for sending requests to which the slave must respond. A number of function codes are pre-defined by the protocol for both setting and getting data on a slave, but other functions may be defined by the user. One goal of this NI Labs release is to provide a better platform for users wishing support additional function codes on either the master or slave sides of the protocol, and to allow users to customize behavior more readily if a particular device does not adhere to the specification. In this library, the request generation and response parsing code is defined by the master function definition.
Description and Code: https://forums.ni.com/t5/Reference-Design-Content/LabVIEW-Modbus-API/ta-p/3524019
Discussion: https://forums.ni.com/t5/NI-Labs-Discussions/NI-LabVIEW-Modbus-API-Discussion/td-p/3373078
