dm_modbus_read_registers Function

public function dm_modbus_read_registers(modbus, address, registers, n) result(rc)

Reads many registers from address. The size of argument registers determines the number of registers to read, unless optional argument n is passed. The function uses the Modbus function code 0x03 (read holding registers).

The function returns the following error codes:

• E_INVALID if argument registers is invalid.
• E_MODBUS if reading the registers failed.
• E_NULL if the Modbus context is not associated.

Arguments

Type	Intent	Optional	Attributes		Name
class(modbus_type),	intent(inout)			::	modbus	Modbus RTU/TCP type.
integer,	intent(in)			::	address	Address to read from.
integer(kind=u2),	intent(inout)			::	registers(:)	Register values (unsigned).
integer,	intent(inout),	optional		::	n	Number of registers to read on input, number of registers read on output.

Return Value integer