cdwork
commented
8 years ago Hello, Vladimir! In project I'm using read/write for external FRAM.
1)For write into FRAM:
Command on client side:
"SYSTem:FRAM:DATA #H100, #14Test"
where:
#H100 - Offset for write in FRAM (is mandatory);
#14Test - Arbitrary block (is mandatory). Length = 4 bytes. Raw data = 'Test'.
and code for parse:
scpi_result_t SCPI_system_fram(scpi_t * context){
int32_t offset,length;
// Parse mandatory offset
if(!SCPI_ParamInt(context,&offset,true)){
return SCPI_RES_ERR;
}
if(offset<0){
SCPI_ErrorPush(context,SCPI_ERROR_ILLEGAL_PARAMETER_VALUE);
return SCPI_RES_ERR;
}
void * data;
// Parse mandatory arbitrary block and receive length of block and pointer to data
if(!SCPI_ParamArbitraryBlock(context,&data,&length,true)){
return SCPI_RES_ERR;
}
// Write to FRAM
fram_write(offset,length,data);
return SCPI_RES_OK;
}2) For read from FRAM:
Command on client side:
"SYSTem:FRAM:DATA? #H100, 4"
where:
#H100 - Offset for read from FRAM (is mandatory);
4 - Length for read from FRAM.
Server return:
"#14Test"
and code for parse:
#define DATA_FRAM_BLOCK_SIZE 32 // Read buffer length
scpi_result_t SCPI_system_framQ(scpi_t * context){
int32_t offset,length;
// Parse mandatory offset
if(!SCPI_ParamInt(context,&offset,true)){
return SCPI_RES_ERR;
}
// Parse mandatory length
if(!SCPI_ParamInt(context,&length,true)){
return SCPI_RES_ERR;
}
// Checking the correct parameters
if(offset<0 || length<0){
SCPI_ErrorPush(context,SCPI_ERROR_ILLEGAL_PARAMETER_VALUE);
return SCPI_RES_ERR;
}
// Read buffer
char data[DATA_FRAM_BLOCK_SIZE];
// Return header of arbitrary block (i.e. "#14")
SCPI_ResultArbitraryBlockHeader(context,length);
int32_t chunk_len;
while(length){
// Limit chunk of read if needed
if(length>DATA_FRAM_BLOCK_SIZE){
chunk_len=DATA_FRAM_BLOCK_SIZE;
}else{
chunk_len=length;
}
//Read from FRAM
fr_read(offset,chunk_len,data);
// Return chunk...
SCPI_ResultArbitraryBlockData(context,data,chunk_len);
offset+=chunk_len;
length-=chunk_len;
// ... and read next chunk if read not complete
}
return SCPI_RES_OK;
}I hope that the example will help.
karakozov
Hello, dear community! Thank you for the open project! I try to apply scpi parser library for my custom device. I have two channels on device. And I need to send data on any device channel and read data from any device channel using SCPI protocol. I add a two custom callback-functions
SOURCE_Arb(scpi_t * context),SOURCE_ArbQ(scpi_t * context)and two patterns (see below) in file scpi-def.c and use examples/test-tcp and PuTTY for testing. I describe my experiments and hope for the help. Thank you!1) When I send data to device, all work fine. SCPI parser give me a pointer on data block and data block size. See listing below:
On client side (putty):
source3:arb #14ABCDOn server side (remote tcp-server):
2) But when I try to get data from device I can't get parameters from incoming request. Or I don't understand how to prepare correct request from client.
On client side (putty):
source3:arb? #14On server side (remote tcp-server): Response available only after 3 - 4 seconds. I suppose that parser wait four bytes data from client, it's necessary send four bytes of any data?
But how I can get how much data user want to get from device channel? Here my additional code. I can provide any additional information.