modbus_mask_write_register.md
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modbus_mask_write_register
Name
modbus_mask_write_register - mask a single register
Synopsis
int modbus_mask_write_register(modbus_t *ctx, int addr, uint16_t and, uint16_t or);
Description
The modbus_mask_write_register() function shall modify the value of the holding register at the address 'addr' of the remote device using the algorithm:
new value = (current value AND 'and') OR ('or' AND (NOT 'and'))
The function uses the Modbus function code 0x16 (mask single register).
Return value
The function shall return 1 if successful. Otherwise it shall return -1 and set errno.