how to write model point as 'symbol'

[Antoniolamb]

Dear all,
It is unclear to me ( if possible ) how I can read/use the model points as symbols .

For example on model 715 I want to set 'OpCtl' to 1 , writing something like
Model715.OpCtl = 'START'

from model_715.json :
""
{
"access": "RW",
"desc": "Commands to PCS. Enumerated value.",
"label": "Set Operation",
"name": "OpCtl",
"size": 1,
"symbols": [
{
"label": "Stop the DER",
"name": "STOP",
"value": 0
},
{
"label": "Start the DER",
"name": "START",
"value": 1
},
{
"label": "Enter Standby Mode",
"name": "ENTER_STANDBY",
"value": 2
},
{
"label": "Exit Standby Mode",
"name": "EXIT_STANDBY",
"value": 3
}
],
"type": "enum16"
}
""
Thanks Antonio