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Users functions #522

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215d626
add users functions support
demiurgspb Feb 25, 2020
107c144
fix minor in last commit
demiurgspb Feb 25, 2020
a14b510
fix2 minor in last commit
demiurgspb Mar 4, 2020
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2 changes: 2 additions & 0 deletions src/modbus-private.h
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Original file line number Diff line number Diff line change
Expand Up @@ -92,6 +92,8 @@ typedef struct _modbus_backend {
struct _modbus {
/* Slave address */
int slave;
/* used only in user-defined functions */
int wanted_resp_data_length;
/* Socket or file descriptor */
int s;
int debug;
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4 changes: 2 additions & 2 deletions src/modbus-rtu.c
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Expand Up @@ -911,11 +911,11 @@ int modbus_rtu_set_serial_mode(modbus_t *ctx, int mode)
struct serial_rs485 rs485conf;

if (mode == MODBUS_RTU_RS485) {
// Get
/* Get */
if (ioctl(ctx->s, TIOCGRS485, &rs485conf) < 0) {
return -1;
}
// Set
/* Set */
rs485conf.flags |= SER_RS485_ENABLED;
if (ioctl(ctx->s, TIOCSRS485, &rs485conf) < 0) {
return -1;
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54 changes: 33 additions & 21 deletions src/modbus.c
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Expand Up @@ -207,7 +207,8 @@ static int send_msg(modbus_t *ctx, uint8_t *msg, int msg_length)
return rc;
}

int modbus_send_raw_request(modbus_t *ctx, const uint8_t *raw_req, int raw_req_length)
int modbus_send_generic_request(modbus_t *ctx,
const uint8_t *raw_req, int raw_req_length, int wanted_resp_data_length)
{
sft_t sft;
uint8_t req[MAX_MESSAGE_LENGTH];
Expand All @@ -226,10 +227,14 @@ int modbus_send_raw_request(modbus_t *ctx, const uint8_t *raw_req, int raw_req_l
return -1;
}

sft.slave = raw_req[0];
ctx->wanted_resp_data_length = wanted_resp_data_length;

sft.slave = raw_req[0];
sft.function = raw_req[1];

/* The t_id is left to zero */
sft.t_id = 0;

/* This response function only set the header so it's convenient here */
req_length = ctx->backend->build_response_basis(&sft, req);

Expand All @@ -242,6 +247,18 @@ int modbus_send_raw_request(modbus_t *ctx, const uint8_t *raw_req, int raw_req_l
return send_msg(ctx, req, req_length);
}

int modbus_send_raw_request(modbus_t *ctx, const uint8_t *raw_req, int raw_req_length)
{
/* The wanted_resp_data_length is set to zero (cause used only in user-defined functions) */
return modbus_send_generic_request(ctx, raw_req, raw_req_length, 0);
}

static uint_fast8_t is_users_function(int function)
{
return ((function >= MODBUS_FC_USERS_RANGE1_LO && function <= MODBUS_FC_USERS_RANGE1_HI) ||
(function >= MODBUS_FC_USERS_RANGE2_LO && function <= MODBUS_FC_USERS_RANGE2_HI));
}

/*
* ---------- Request Indication ----------
* | Client | ---------------------->| Server |
Expand Down Expand Up @@ -270,19 +287,17 @@ static uint8_t compute_meta_length_after_function(int function,
}
} else {
/* MSG_CONFIRMATION */
switch (function) {
case MODBUS_FC_WRITE_SINGLE_COIL:
case MODBUS_FC_WRITE_SINGLE_REGISTER:
case MODBUS_FC_WRITE_MULTIPLE_COILS:
case MODBUS_FC_WRITE_MULTIPLE_REGISTERS:
if ((function == MODBUS_FC_WRITE_SINGLE_COIL) ||
(function == MODBUS_FC_WRITE_SINGLE_REGISTER) ||
(function == MODBUS_FC_WRITE_MULTIPLE_COILS) ||
(function == MODBUS_FC_WRITE_MULTIPLE_REGISTERS))
length = 4;
break;
case MODBUS_FC_MASK_WRITE_REGISTER:
else if (function == MODBUS_FC_MASK_WRITE_REGISTER)
length = 6;
break;
default:
else if (is_users_function(function))
length = 0;
else
length = 1;
}
}

return length;
Expand All @@ -293,7 +308,7 @@ static int compute_data_length_after_meta(modbus_t *ctx, uint8_t *msg,
msg_type_t msg_type)
{
int function = msg[ctx->backend->header_length];
int length;
int length = 0;

if (msg_type == MSG_INDICATION) {
switch (function) {
Expand All @@ -304,18 +319,15 @@ static int compute_data_length_after_meta(modbus_t *ctx, uint8_t *msg,
case MODBUS_FC_WRITE_AND_READ_REGISTERS:
length = msg[ctx->backend->header_length + 9];
break;
default:
length = 0;
}
} else {
/* MSG_CONFIRMATION */
if (function <= MODBUS_FC_READ_INPUT_REGISTERS ||
function == MODBUS_FC_REPORT_SLAVE_ID ||
function == MODBUS_FC_WRITE_AND_READ_REGISTERS) {
if ( function <= MODBUS_FC_READ_INPUT_REGISTERS ||
function == MODBUS_FC_REPORT_SLAVE_ID ||
function == MODBUS_FC_WRITE_AND_READ_REGISTERS )
length = msg[ctx->backend->header_length + 1];
} else {
length = 0;
}
else if (is_users_function(function))
length = ctx->wanted_resp_data_length;
}

length += ctx->backend->checksum_length;
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8 changes: 8 additions & 0 deletions src/modbus.h
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Original file line number Diff line number Diff line change
Expand Up @@ -71,6 +71,11 @@ MODBUS_BEGIN_DECLS
#define MODBUS_FC_MASK_WRITE_REGISTER 0x16
#define MODBUS_FC_WRITE_AND_READ_REGISTERS 0x17

#define MODBUS_FC_USERS_RANGE1_LO 0x41 /* 65-72 */
#define MODBUS_FC_USERS_RANGE1_HI 0x48
#define MODBUS_FC_USERS_RANGE2_LO 0x64 /* 100-110 */
#define MODBUS_FC_USERS_RANGE2_HI 0x6E

#define MODBUS_BROADCAST_ADDRESS 0

/* Modbus_Application_Protocol_V1_1b.pdf (chapter 6 section 1 page 12)
Expand Down Expand Up @@ -227,6 +232,9 @@ MODBUS_API modbus_mapping_t* modbus_mapping_new(int nb_bits, int nb_input_bits,
int nb_registers, int nb_input_registers);
MODBUS_API void modbus_mapping_free(modbus_mapping_t *mb_mapping);

MODBUS_API int modbus_send_generic_request(modbus_t *ctx,
const uint8_t *raw_req, int raw_req_length, int wanted_resp_data_length);

MODBUS_API int modbus_send_raw_request(modbus_t *ctx, const uint8_t *raw_req, int raw_req_length);

MODBUS_API int modbus_receive(modbus_t *ctx, uint8_t *req);
Expand Down