How do I solve "-307" error on ZKTeco SDK? - access-control

Question

Hello everyone and thanks for reading this problem.
I have a solution in C# using the zkemkeeper dll to get the records from some access control devices. When I "ping" them, there isn't any problem, but when I try to connect to them (Using my solution or the standalone demo to get attendance) I get the "-307" error with the "Unable to connect message". That's not very clear and I would really aprecciate if someone can explain what this error is (please!!!!). I would really like to understand these errors myself, so, where can I find all the definition of these errors?
In short:
1.- What is the problem regarding the "-307" error?
2.- Is there any place where all these errors are documented?
Thanks in advance!!

Answer 1

enter image description here
maybe you should check your device, you can ping them

Answer 2

Attention
The dwErrorCode parameter specifies the error code. The values are described as follows:
During connection, the following error codes may be returned:
0 Connected successfully
-1 Failed to invoke the interface
-2 Failed to initialize
-3 Failed to initialize parameters
-5 Data mode read error
-6 Wrong password
-7 Reply error
-8 Receive timeout
-307 Connection timeout
In invoking other interfaces, the following error codes may be returned:
-201 Device is busy
-199 New Mode
-103 device send back error of face version error
-102 face template version error, like 8.0 face template send to 7.0 device
-101 malloc memory failed
-100 Not supported or the data does not exist
-10 The length of transmitted data is incorrect
-5 Data already exists
-4 Insufficient space
-3 Wrong size
-2 File read/write error
-1 The SDK is not initialized and needs to be reconnected
0 Data not found or duplicate data
1 Correct operation
4 Parameter error
101 Buffer allocation error
102 repeat invoking
Underlying error codes:
-12001 Socket creation timeout (connection timeout)
-12002 Insufficient memory
-12003 Wrong Socket version
-12004 Not TCP protocol
-12005 Waiting timeout
-12006 Data transmission timeout
-12007 Data reading timeout
-12008 Failed to read Socket
-13009 Waiting event error
-13010 Exceeded retry attempts
-13011 Wrong reply ID
-13012 Checksum error
-13013 Waiting event timeout
-13014 DIRTY_DATA
-13015 Buffer size too small
-13016 Wrong data length
-13017 Invalid data read1
-13018 Invalid data read2
-13019 Invalid data read3
-13020 Data loss
-13021 Memory initialization error
-15001 Invoking return value of status key issued by SetShortkey interface repeatedly
-15002 Invoking return value of description issued by SetShortkey interface repeatedly
-15003 The two level menu is not opened in the device, and the data need not be issued
getdevicedata and setdevicedata invocation error codes
-15100 Error occurs in obtaining table structure
-15101 The condition field does not exist in the table structure
-15102 Inconsistency in the total number of fields
-15103 Inconsistency in sorting fields
-15104 Memory allocation error
-15105 Data parsing error
-15106 Data overflow as the transmitted data exceeds 4M
-15108 Invalid options
-15113 Data parsing error: table ID not found
-15114 A data exception is returned as the number of fields is smaller than or equal to 0
-15115 A data exception is returned as the total number of table fields is inconsistent with the
total number of fields of the data
Firmware error codes:
2000 Return OK to execute
-2001 Return Fail to execute command
-2002 Return Data
-2003 Regstered event occorred
-2004 Return REPEAT Command
-2005 Return UNAUTH Command
0xffff Return Unknown Command
-4999 Device parameter read error
-4998 Device parameter write error
-4997 The length of the data sent by the software to the device is incorrect
228
229
-4996 A parameter error exists in the data sent by the software to the device
-4995 Failed to add data to the database
-4994 Failed to update the database
-4993 Failed to read data from the database
-4992 Failed to delete data in the database
-4991 Data not found in the database
-4990 The data amount in the database reaches the limit
-4989 Failed to allocate memory to a session
-4988 Insufficient space in the memory allocated to a session
-4987 The memory allocated to a session overflows
-4986 File does not exist
-4985 File read failure
-4984 File write failure
-4983 Failed to calculate the hash value
-4982 Failed to allocate memory
Note
This interface is applicable to the new architecture firmware.