modbus_read_input_registers3
Read many input registers
Usage
int modbus_read_input_registers(modbus_t *ctx, int addr, int nb, uint16_t *dest);
Overview
The modbus_read_input_registers() function shall read the content of the nb input registers to address addr of the remote device. The result of the reading is stored in dest array as word values (16 bits).
You must take care to allocate enough memory to store the results in dest (at least nb * sizeof(uint16_t)).
The function uses the Modbus function code 0x04 (read input registers). The holding registers and input registers have different historical meaning, but nowadays it’s more common to use holding registers only.
Return value
The function shall return the number of read input registers if successful. Otherwise it shall return -1 and set errno.
Errors
EMBMDATA
Too many bits requested
Releases
6 releases since Debian 7 (Wheezy); the text changed 5 times.