Kramer Electronics SP-14 - Manual (Page 14)

3.2.1.3 Attribute
The attribute identifier specifies the attribute of the parameter this action or request is related to.
Identifier
Value Base 64 Description
avParamAttr_avail 0 AA Availability of the parameter.
avParamAttr_availValue 1 AB Availability of the specific parameter value.
avParamAttr_min 2 AC Minimum valid parameter value.
avParamAttr_max 3 AD Maximum valid parameter value.
avParamAttr_value 4 AE Parameter value (live).
avParamAttr_e2value 5 AF Parameter value (persistent).
Some attribute are not applicable to some functions as detailed below.
The avParamAttr_value and avParamAttr_e2value attributes allow the separation between the
settings in the Audio/Visual engine and the settings in the persistent storage within the unit.
For the get function it is recommended to use the avParamAttr_e2value attribute exclusively.
In the case of the set function the two attribute must be used together as explained in 3.2.5 Set.
For the get string and set string functions there is no difference between the avParamAttr_value and
avParamAttr_e2value attributes.
Note avParamAttr_e2value may also be referred to as “NV”, “non-volatile” or “save”.
3.2.1.4 API Debugging (Interpretation)
For the purpose of debugging, if byte 16 is set to an ASCII ‘?’ the unit will return text interpreting what
it has received. This looks like this:
Func:0, Param:0, Attr:0, Val:00000000
The values for Func, Param, Attr are in denary (base 10) and the value for Val is in hexadecimal.
3.2.2 Parameter Reply Packet format
Each function will return one of two packets, one for success and one for an error.
The following table summarises the reply packets for each of the functions.
Function Function
Identifier
Reply Packet
Type Reply
Packet
Size Comment
query avrFunc_query Success with value 9 bytes See 3.2.2.2
get avrFunc_get Success with value 9 bytes See 3.2.2.2
set avrFunc_set Success 3 bytes See 3.2.2.1
gets avrFunc_gets Success with string variable Expect 103 bytes minimum. See
3.2.2.3
sets avrFunc_sets Success 3 bytes See 3.2.2.1
all Error 15 bytes See 3.2.2.4
For Ethernet it is necessary to expect the reply to be at least 500 bytes. The reply packet is currently
padded to 500 bytes but this is may be removed in the future.
3.2.2.1 Success Reply Packet
For a function that does not return any value the reply packet of a successful call will look like this:
1 2 3
‘O’ ‘K’ ‘.’