CRC16PLCopen motion icon

FunctionClosedA function calculates a result according to the current value of its inputs. A function has no internal data and is not linked to declared instances. - calculates a CRC16 on the characters of a string

Inputs

IN : STRING character string

Outputs

Q : INT     CRC16 calculated on all the characters of the string.

Remarks

In FFLD language, the input rung (EN) enables the operation, and the output rung keeps the same value as the input rung. In ILClosed"Instruction list" This is a low-level language and resembles assembly language, the input parameter (IN) must be loaded in the current result before calling the function.

The function calculates a ModbusClosedModBus is a serial communications protocol and is now the most commonly available means of connecting industrial electronic devices. ModBus is often used to connect a supervisory computer with a remote terminal unit in supervisory control and data acquisition (SCADA) systems. Versions of the ModBus protocol exist for serial port and Ethernet (it is widely used with TCP/IP over Ethernet) CRC16, initialized at 16#FFFF value.

ST Language

Q := CRC16 (IN);

FBD Language

FFLD Language

(* The function is executed only if EN is TRUE *)
(* ENO is equal to EN *)

IL Language:

Op1: LDClosed"Ladder diagram" Ladder logic is a method of drawing electrical logic schematics. It is now a very popular graphical language for programming Programmable Logic Controllers (PLCs). It was originally invented to describe logic made from relays. The name is based on the observation that programs in this language resemble ladders, with two vertical "rails" and a series of horizontal "rungs" between them    IN
     CRC16
     ST    Q