ArcGIS Tile Cache

The below is an example setting for using an ArcGIS Tile Cache.

{
 "roads":{
  "type": "ArcGISCache",
  "url": "Server Name/ArcGIS/rest/services/Map Name/MapServer",
  "resolutions" : [
   92.6043518753704,
   26.4583862501058,
   13.2291931250529,
   6.61459656252646,
   5.29167725002117,
   3.96875793751588,
   2.64583862501058,
   1.32291931250529,
   0.661459656252646,
   0.264583862501058],
  "tileSize": [512, 512],
  "tileOrigin" : [-5220400, 4470200],
  "projection": "EPSG:27700",
  "projectionDef": "+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +datum=OSGB36 +units=m +no_defs ",
  "units": "m",
  "restrictedExtent": [230000,629267,320000,704092],
  "maxExtent": [230000,629267,320000,704092]
 }
}

How do I obtain the settings required for the above?

Most of the required settings can be determined by querying the map layer to get its properties, by appending "?f=json&pretty=true" to the end of the url in a browser, e.g.:

http://server name/ArcGIS/rest/services/map name/mapserver?f=json&pretty=true

This will return a JSON description of the map from which the settings can be obtained:

"type":	this value must be set to "ArcGISCache"
"url":	This is the base URL for the ArcGIS Tile Cache.
"resolutions":	Enter a list of all the resolutions required. Find the section that begins with "lods" under "tileInfo" and list the resolution values separated by commas. e.g. "resolutions" : [ 42.3334180001693, 21.1667090000847, 10.5833545000423],
"tileSize":	This is in the "tileInfo" section. List the values for "rows" and "columns" separated by a comma. e.g. [256, 256] or [512, 512].
"tileOrigin":	List the "x" and "y" found under "tileInfo" > "origin"
"projection":	Refer to Projections page for details.
"projectionDef":	Refer to Projections page for details.
"units":	must be entered as "m", as shown in the example. m = metres.
"restrictedExtent":	List the xmin, ymin, xmax, ymax values. These are shown under the "fullExtent". It is specified as a comma separated list of coordinates inside the square brackets as follows: Minimum X,Minimum Y,Maximum X,Maximum Y
"maxExtent":	Set to the same as the "fullExtent" entered in the "restrictedExtent" entry. It is specified as a comma separated list of coordinates inside the square brackets as follows: Minimum X,Minimum Y,Maximum X,Maximum Y