Difference between revisions of "SimpleMotion V2 API documentation"

Revision as of 19:58, 28 August 2015

This article is work in progress. Do not rely any of it's content until this notice is removed. You are welcome contribute by editing this page.

Files

simplemotion.h

The header file that declares API functions and constants used in SMV2 programs. Include this file in the C-file where SMV2 is used.

simplemotion.dll or smv.dll

A Win32 dynamic library. Place this file in application .exe folder if program is linked against the DLL. If project is being compiled with GNU GCC, then all library .c files may be added in the project to compile library statically in the program thus eliminate the need of .dll.

simplemotion.lib or smv.lib

A library file needed by some Microsoft C/C++ development tools to allow usage of DLL file. Most of other tools don't need these.

Types

SMV2 library uses custom integer types in order to have explicitly defined bit lengths. All types translate to standard C-types.

typedef long smbus;
typedef unsigned long smuint32;
typedef unsigned short smuint16;
typedef unsigned char smuint8;
typedef long smint32;
typedef short smint16;
typedef char smint8;
typedef char smbool;
#define smtrue 1
#define smfalse 0
typedef int SM_STATUS;
typedef smuint8 smaddr;
typedef enum _smVerbosityLevel {Off,Low,Mid,High,Trace} smVerbosityLevel;

SM_STATUS is returned by most of function calls and indicate the success or failure of the call. Multiple states are possible simultaneously, i.e. function may return integer value 40 which is a sum of 32 and 8 meaning both SM_ERR_COMMUNICATION and SM_ERR_LENGTH are active. Possible return values of SM_STATUS:

SM_NONE (integer value 0)

Never returned

SM_OK (integer value 1)

Call completed successfully

SM_ERR_NODEVICE (integer value 2)

Invalid smbus handle given or port not open

SM_ERR_BUS (integer value 4)

RS485 communication device error

SM_ERR_COMMUNICATION (integer value 8)

Invalid reply or no reply received from target device. Typical reasons: inexisting nodeAddress given or signal quality problem (see EMI and Device connection troubleshooting)

SM_ERR_PARAMETER (integer value 16)

Illegal parameter value given

SM_ERR_LENGTH (integer value 32)

Command queue length exceeded maximum size or received return data length differs from expected length. Typical reasons: invalid/exceeded usage of queued commands or same as SM_ERR_COMMUNICATION reasons.

Function reference

General

devicename

"USB2VSD" or com port as "COMx" where x=1-n, i.e. "COM15". In UNIX systems this is device path such as "/dev/ttyUSB0".

return value

handle to be used with all other commands, -1 if fails

Usage:

smbus bushandle;
bushandle=smOpenBus("COM5");
if(bushandle<0)
{
  //error occurred
}

return value

a SM_STATUS value, i.e. SM_OK if command succeed. The SM_STATUS return value from all other functions have similar meaning.

Usage:

smCloseBus(bushandle);

level

set verbosity level of debugging output. Enum choices are Off,Low,Mid,High and Trace.

stream

A pointer to output stream such as stderr, stdout or a file handle.

For example, this returns SM_OK if all past function calls completed without errors (does not report errors that target device may have, just SM communication related errors). I.e. will return SM_OK|SM_ERR_LENGTH (=decimal value 33) in case of some command returned SM_OK and another SM_ERR_LENGTH.

This function is provided to ease error checking by eliminating the need to inspect return value of each individual function call separately. Instead, programmer may occasionally call this function to check if any errors have occurred during longer period of time.

Communication

/** Simple read & write of parameters with internal queueing, so only one call needed. Use these for non-time critical operations. */