MBM_FC15_CoilWr() - Modbus-M

This function is called from YOUR application code to write to multiple coils on a Modbus slave.

Prototype

CPU_INT16U  MBM_FC15_CoilWr (MODBUS_CH  *pch, 
                             CPU_INT08U  slave_node,
                             CPU_INT16U  slave_addr,
                             CPU_INT08U *p_coil_tbl,
                             CPU_INT16U  nbr_coils);

Arguments

pch

is a pointer to the channel (returned by MB_CfgCh()). This pointer specifies onto which channel the Modbus master will be communicating on. Of course, ‘pch’ must have been configured as a Master when you configured the channel.

slave_node

specifies the slave ‘node address’ that you desire to change the coil values. This can be a number between 1 and 255 but needs to match the number assigned to the slave node.

slave_addr

specifies the start address of the coils that you want to change. This can be from 0 to 65535.

p_coil_tbl

is an array of values corresponding to the desired values for the coils. The format is assumed to be as follows:

                          MSB                               LSB
                          B7   B6   B5   B4   B3   B2   B1   B0
                          -------------------------------------
          p_coil_tbl[0]   #8   #7                  #1
          p_coil_tbl[1]   #16  #15                 #9
               :
               :

nbr_coils

specifies the number of coils you are changing. Of course, the array pointed to by p_coil_tbl must contain the corresponding number of entries.

Returned Value

MODBUS_ERR_NONE

if the call was successful.

MODBUS_ERR_RX

if a response was not received from the slave within the timeout specified for this channel (see MB_CfgCh()).

MODBUS_ERR_SLAVE_ADDR

If the transmitted slave address doesn't correspond to the received slave address

MODBUS_ERR_FC

If the transmitted function code doesn't correspond to the received function code

MODBUS_ERR_BYTE_COUNT

If the expected number of bytes to receive doesn't correspond to the number of bytes received.

Notes / Warnings

None

Called By

Your Modbus master application.