LJM Timeout Configs
All timeouts are in units of milliseconds.
ListAll timeouts
These timeouts control how long LJM waits for a response to ListAll requests.
LJM_LISTALL_TIMEOUT_MS_ETHERNET
LJM_LISTALL_TIMEOUT_MS_ETHERNET is a numerical readable-writable LJM library configuration which sets how long in milliseconds LJM waits for a response to an Ethernet connection discovery request.
The constant LJM_LISTALL_TIMEOUT_MS_ETHERNET can be used interchangeably with the string "LJM_LISTALL_TIMEOUT_MS_ETHERNET".
The default timeout is 900 ms.
LJM_LISTALL_NUM_ATTEMPTS_ETHERNET
LJM_LISTALL_NUM_ATTEMPTS_ETHERNET is a numerical readable-writable LJM library configuration which sets how many times LJM will retry device Ethernet discovery requests.
The constant LJM_LISTALL_NUM_ATTEMPTS_ETHERNETcan be used interchangeably with the string "LJM_LISTALL_NUM_ATTEMPTS_ETHERNET".
The default value is 2.
LJM_LISTALL_TIMEOUT_MS_WIFI
LJM_LISTALL_TIMEOUT_MS_WIFI is a numerical readable-writable LJM library configuration which sets how long in milliseconds LJM waits for a response to a WiFi connection discovery request.
The constant LJM_LISTALL_TIMEOUT_MS_WIFI can be used interchangeably with the string "LJM_LISTALL_TIMEOUT_MS_WIFI".
The default timeout is 1000 ms.
LJM_LISTALL_NUM_ATTEMPTS_WIFI
LJM_LISTALL_NUM_ATTEMPTS_WIFI is a numerical readable-writable LJM library configuration which sets how many times LJM will retry device WiFi discovery requests.
The constant LJM_LISTALL_NUM_ATTEMPTS_WIFIcan be used interchangeably with the string "LJM_LISTALL_NUM_ATTEMPTS_WIFI".
The default value is 2.
Open timeouts
These timeouts control how long LJM waits for a response at a given IP.
LJM_OPEN_TCP_DEVICE_TIMEOUT_MS may be used to set both open timeouts at the same time.
If you use "ANY" for the identifier to LJM_OpenS/LJM_Open, ListAll is called internally to find device connections. The ListAll timeouts will be used instead of the open timeouts given above.
Command-Response send / receive () timeouts
These timeouts control the maximum amount of time LJM will wait for a response during command-response communication.
LJM_SEND_RECEIVE_TIMEOUT_MS may be used to set all three send / receive timeouts at the same time.
Stream receive timeout
These configs control how LJM waits for packets during stream.
These configs are especially relevant to externally-clocked stream.
Details
One command-response operation (as performed by a function like LJM_eReadName, for example) may take longer than the timeout for that connection type. This is because there are multiple timeout periods -- one to send the command and another to receive the response.
Setting a new timeout value will not affect pending timeouts.
Setting a timeout value to 0 sets an infinite timeout.
Relevant Functions
To read a timeout config, use LJM_ReadLibraryConfigS.
To write a timeout config, use LJM_WriteLibraryConfigS or LJM_LoadConfigurationFile.
Example
Read LJM_ETHERNET_SEND_RECEIVE_TIMEOUT_MS, set LJM_ETHERNET_SEND_RECEIVE_TIMEOUT_MS, then read it again
char ErrorString[LJM_MAX_NAME_SIZE];
double Value = 0;
int LJMError = LJM_ReadLibraryConfigS(LJM_ETHERNET_SEND_RECEIVE_TIMEOUT_MS, &Value);
if (LJMError != 0) {
LJM_ErrorToString(LJMError, ErrorString);
printf("LJM_ReadLibraryConfigS error: %s\n", ErrorString);
}
printf("The default for LJM_ETHERNET_SEND_RECEIVE_TIMEOUT_MS is %.00f milliseconds\n", Value);
Value = 3000;
printf("Setting LJM_ETHERNET_SEND_RECEIVE_TIMEOUT_MS to %.00f milliseconds\n", Value);
LJMError = LJM_WriteLibraryConfigS(LJM_ETHERNET_SEND_RECEIVE_TIMEOUT_MS, Value);
if (LJMError != 0) {
LJM_ErrorToString(LJMError, ErrorString);
printf("LJM_WriteLibraryConfigS error: %s\n", ErrorString);
}
LJMError = LJM_ReadLibraryConfigS(LJM_ETHERNET_SEND_RECEIVE_TIMEOUT_MS, &Value);
if (LJMError != 0) {
LJM_ErrorToString(LJMError, ErrorString);
printf("LJM_ReadLibraryConfigS error: %s\n", ErrorString);
}
printf("LJM_ETHERNET_SEND_RECEIVE_TIMEOUT_MS is now %.00f milliseconds\n", Value);Possible output:
The default for LJM_ETHERNET_SEND_RECEIVE_TIMEOUT_MS is 2000 millisecondsSetting LJM_ETHERNET_SEND_RECEIVE_TIMEOUT_MS to 3000 millisecondsLJM_ETHERNET_SEND_RECEIVE_TIMEOUT_MS is now 3000 milliseconds
For more LJM configurations, see Library Configuration Functions.
Related Errors
The below errors can sometimes occur if the send/receive timeout configuration is too low due to higher than expected connection latency. Increasing the send/receive timeout configurations can sometimes help avoid these errors, but they may also indicate a more general connection issue. We would recommend seeing our troubleshooting application notes for USB and Ethernet.
LJME_NO_RESPONSE_BYTES_RECEIVED
LJME_INCORRECT_NUM_RESPONSE_BYTES_RECEIVED