1MODBUS_READ_BITS(3)            Libmodbus Manual            MODBUS_READ_BITS(3)
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NAME

6       modbus_read_bits - read many bits
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SYNOPSIS

9       int modbus_read_bits(modbus_t *ctx, int addr, int nb, uint8_t *dest);
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DESCRIPTION

12       The modbus_read_bits() function shall read the status of the nb bits
13       (coils) to the address addr of the remote device. The result of reading
14       is stored in dest array as unsigned bytes (8 bits) set to TRUE or
15       FALSE.
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17       You must take care to allocate enough memory to store the results in
18       dest (at least nb * sizeof(uint8_t)).
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20       The function uses the Modbus function code 0x01 (read coil status).
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RETURN VALUE

23       The modbus_read_bits() function shall return the number of read bits if
24       successful. Otherwise it shall return -1 and set errno.
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ERRORS

27       EMBMDATA
28           Too many bits requested
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SEE ALSO

31       modbus_write_bit(3) modbus_write_bits(3)
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AUTHORS

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

38        1. stephane.raimbault@gmail.com
39           mailto:stephane.raimbault@gmail.com
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43libmodbus 3.0.6                   04/02/2014               MODBUS_READ_BITS(3)