/**
* Send a Modbus write multiple registers command.
*
* @param modbus Previously initialized Modbus device structure.
* @param address The Modbus address of the first register to write.
* @param nb_registers The number of registers to write.
* @param registers Buffer holding all the registers values to write.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments,
* SR_ERR_DATA upon invalid data, or SR_ERR on failure.
*/
SR_PRIV int sr_modbus_write_multiple_registers(struct sr_modbus_dev_inst*modbus,
int address, int nb_registers, uint16_t *registers)
{
uint8_t request[6 + (2 * nb_registers)], reply[5];
int ret;
if (address < 0 || address > 0xFFFF
|| nb_registers < 1 || nb_registers > 123 || !registers)
return SR_ERR_ARG;
W8(request + 0, MODBUS_WRITE_MULTIPLE_REGISTERS);
WB16(request + 1, address);
WB16(request + 3, nb_registers);
W8(request + 5, 2 * nb_registers);
memcpy(request + 6, registers, 2 * nb_registers);
ret = sr_modbus_request_reply(modbus, request, sizeof(request),
reply, sizeof(reply));
if (ret != SR_OK)
return ret;
if (sr_modbus_error_check(reply))
return SR_ERR_DATA;
if (memcmp(request, reply, sizeof(reply)))
return SR_ERR_DATA;
return SR_OK;
}
/**
* Send a Modbus read holding registers command and receive the corresponding
* registers values.
*
* @param modbus Previously initialized Modbus device structure.
* @param address The Modbus address of the first register to read, or -1 to
* read the reply of a previouly sent read registers command.
* @param nb_registers The number of registers to read.
* @param registers Buffer to store all the received registers values,
* or NULL to send the read holding registers command
* without reading the reply.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments,
* SR_ERR_DATA upon invalid data, or SR_ERR on failure.
*/
SR_PRIV int sr_modbus_read_holding_registers(struct sr_modbus_dev_inst *modbus,
int address, int nb_registers, uint16_t *registers)
{
uint8_t request[5], reply[2 + (2 * nb_registers)];
int ret;
if (address < -1 || address > 0xFFFF
|| nb_registers < 1 || nb_registers > 125)
return SR_ERR_ARG;
W8(request + 0, MODBUS_READ_HOLDING_REGISTERS);
WB16(request + 1, address);
WB16(request + 3, nb_registers);
if (address >= 0) {
ret = sr_modbus_request(modbus, request, sizeof(request));
if (ret != SR_OK)
return ret;
}
if (registers) {
ret = sr_modbus_reply(modbus, reply, sizeof(reply));
if (ret != SR_OK)
return ret;
if (sr_modbus_error_check(reply))
return SR_ERR_DATA;
if (reply[0] != request[0] || R8(reply + 1) != (uint8_t)(2 * nb_registers))
return SR_ERR_DATA;
memcpy(registers, reply + 2, 2 * nb_registers);
}
return SR_OK;
}
/**
* Send a Modbus read coils command and receive the corresponding coils values.
*
* @param modbus Previously initialized Modbus device structure.
* @param address The Modbus address of the first coil to read, or -1 to read
* the reply of a previouly sent read coils command.
* @param nb_coils The number of coils to read.
* @param coils Buffer to store all the received coils values (1 bit per coil),
* or NULL to send the read coil command without reading the reply.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments,
* SR_ERR_DATA upon invalid data, or SR_ERR on failure.
*/
SR_PRIV int sr_modbus_read_coils(struct sr_modbus_dev_inst *modbus,
int address, int nb_coils, uint8_t *coils)
{
uint8_t request[5], reply[2 + (nb_coils + 7) / 8];
int ret;
if (address < -1 || address > 0xFFFF || nb_coils < 1 || nb_coils > 2000)
return SR_ERR_ARG;
W8(request + 0, MODBUS_READ_COILS);
WB16(request + 1, address);
WB16(request + 3, nb_coils);
if (address >= 0) {
ret = sr_modbus_request(modbus, request, sizeof(request));
if (ret != SR_OK)
return ret;
}
if (coils) {
ret = sr_modbus_reply(modbus, reply, sizeof(reply));
if (ret != SR_OK)
return ret;
if (sr_modbus_error_check(reply))
return SR_ERR_DATA;
if (reply[0] != request[0] || R8(reply + 1) != (uint8_t)((nb_coils + 7) / 8))
return SR_ERR_DATA;
memcpy(coils, reply + 2, (nb_coils + 7) / 8);
}
return SR_OK;
}
static int maynuo_m97_cmd(struct sr_modbus_dev_inst *modbus,
enum maynuo_m97_mode cmd)
{
uint16_t registers[1];
WB16(registers, cmd);
return sr_modbus_write_multiple_registers(modbus, CMD, 1, registers);
}
/**
* Send a Modbus write coil command.
*
* @param modbus Previously initialized Modbus device structure.
* @param address The Modbus address of the coil to write.
* @param value The new value to assign to this coil.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments,
* SR_ERR_DATA upon invalid data, or SR_ERR on failure.
*/
SR_PRIV int sr_modbus_write_coil(struct sr_modbus_dev_inst *modbus,
int address, int value)
{
uint8_t request[5], reply[5];
int ret;
if (address < 0 || address > 0xFFFF)
return SR_ERR_ARG;
W8(request + 0, MODBUS_WRITE_COIL);
WB16(request + 1, address);
WB16(request + 3, value ? 0xFF00 : 0);
ret = sr_modbus_request_reply(modbus, request, sizeof(request),
reply, sizeof(reply));
if (ret != SR_OK)
return ret;
if (sr_modbus_error_check(reply))
return SR_ERR_DATA;
if (memcmp(request, reply, sizeof(reply)))
return SR_ERR_DATA;
return SR_OK;
}
