Index

Terms

Term	Brief
DHCP	Domain Host Control Protocol
DNS	Domain Name Server
Static IP	Dedicated Internet Protocol Address assigned to a device on network
RS485	Serial communication interface for industrial applications over long distances
Baud Rate	Data transmitted at bits/second
Start Bit	Prepares reciever for arrival of data
Parity bit	Indicates parity, used to check the integrity of data.
Stop bit	Resets state to enable triggering of next sequence
Internal Modbus RTU	Remote Terminal Unit for serial communication on modbus network
LAN	Local Area Network (LAN). A collection of devices connected in one physical location, such as a building, office, or home.
HMI	Human Machine Interface
VFD	Variable Frequency Drive
PLC	Programmable Logic Controller
TCP	Transmission Control Protocol, Network standard to establish connection between two network sockets.
Internal System Bus	Limited to the CPU Architecture
Master (Client)	Recieves requests and delegats to ‘Slave’ units, central unit, controller
Slave (Server)	subordinate to master unit, responsible to process requests sent from Master
SMTP	Secure Mail Server
Port	A unique numeric identifier for a connection endpoint to direct data to a specific service

Standard Ports

Port	Designation
502	Modbus TCP/IP standard communication port used by clients and servers to send and recieve data.
25	Common SMTP, best for SMTP relay, does not support secure transmission.
587	Default SMTP for best for SMTPS, supports secure transmission via TLS.
465	Legacy SMPT Port, not recommended but is still supported.

Registers

Register Type	Address Range	Description
Coils	00001 - 09999	Binary outputs (ON/OFF), read or write
Discrete Inputs	10001 - 19999	Binary inputs (ON/OFF), read-only
Input Registers	30001 - 39999	Analog inputs (16-bit), read-only
Holding Registers	40001 - 49999	Analog outputs or configurations (16-bit), read/write

DATA Order

Orders	Description
Big Endian	The most significant byte (MSB) is stored first at the lowest memory address.
Little Endian	The least significant byte (LSB) is stored first at the lowest memory address.
Big Endian Reversed	Byte order is stored as Little Endian, but with the higher-order bytes placed first in memory.
Little Endian Reversed	Byte order is stored like Big Endian, but the least significant byte is placed first in memory.