1MODBUS_SET_SLAVE(3)            Libmodbus Manual            MODBUS_SET_SLAVE(3)
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NAME

6       modbus_set_slave - set slave number in the context
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SYNOPSIS

9       int modbus_set_slave(modbus_t *ctx, int slave);
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DESCRIPTION

12       The modbus_set_slave() function shall set the slave number in the
13       libmodbus context.
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15       The behavior depends of network and the role of the device:
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17       RTU
18           Define the slave ID of the remote device to talk in master mode or
19           set the internal slave ID in slave mode. According to the protocol,
20           a Modbus device must only accept message holing its slave number or
21           the special broadcast number.
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23       TCP
24           The slave number is only required in TCP if the message must reach
25           a device on a serial network. The special value MODBUS_TCP_SLAVE
26           (0xFF) can be used in TCP mode to restore the default value.
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28       The broadcast address is MODBUS_BROADCAST_ADDRESS. This special value
29       must be use when you want all Modbus devices of the network receive the
30       request.
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RETURN VALUE

33       The modbus_set_slave() function shall return 0 if successful. Otherwise
34       it shall return -1 and set errno to one of the values defined below.
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ERRORS

37       EINVAL
38           The slave number is invalid.
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AUTHORS

41       The libmodbus documentation was written by Stéphane Raimbault
42       <stephane.raimbault@gmail.com[1]>
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NOTES

45        1. stephane.raimbault@gmail.com
46           mailto:stephane.raimbault@gmail.com
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50libmodbus 3.0.8                   07/31/2019               MODBUS_SET_SLAVE(3)