update README

README.md

@@ -3,6 +3,31 @@ e3-ADSpinnaker
 ======
 ESS Site-specific EPICS module : ADSpinnaker
 
+## Spinnaker Libraries
+
+* With the default shared libraries within spinnakerSupport and its header files return the following error messages:
+
+```
+ADSpinnakerConfig("PG", 19299225, 0x1, 0)                                                                                      
+terminate called after throwing an instance of 'Spinnaker::Exception'                                                          
+  what():  Spinnaker: System instance cannot be acquired. [-1012]    
+```
+
+in `Ubuntu 18.04.3 LTS (GNU/Linux 5.0.0-27-generic x86_64)`
+
+* The latest (current) SpinnakerSDK is 1.26.0.31 in [1]. And one should install the following packages
+  - `libspinnaker-1.26.0.31_amd64-dev.deb`
+  - `libspinnaker-1.26.0.31_amd64.de`
+  - `libspinnaker-c-1.26.0.31_amd64.deb`
+  - `libspinnaker-c-1.26.0.31_amd64-dev.deb`
+
+* If one would like to switch between SpinnakerSDK and areaDetector libraries, one can use `SUPPORT_EXTERNAL` defined in
+`configure/CONFIG_OPTIONS`
+
+  - AreaDetector : `echo "SUPPORT_EXTERNAL:=NO" > configure/CONFIG_OPTIONS.local`
+  - SpinnakerSDK : Default one
+
+
 ## OS
 
 We cannot use this on CentOS7 based system, I think, we can do in CentOS8 in near future, because of 
@@ -22,3 +47,9 @@ We cannot use this on CentOS7 based system, I think, we can do in CentOS8 in nea
 /lib64/libstdc++.so.6: version `GLIBCXX_3.4.20' not found (required by libNodeMapData_gcc540_v3_0.so)
 /lib64/libstdc++.so.6: version `GLIBCXX_3.4.21' not found (required by libNodeMapData_gcc540_v3_0.so)
 ```
+
+
+## Reference
+[1] https://flir.app.boxcn.net/v/SpinnakerSDK/folder/74729115388 
+
+