Create reactive form Array with different Validations in array

I recently started on Angular4 reactive Forms, i want to create a form array based on below Structure

"ContactPoints":
[{"ContactPointID":33,"EntityID":9,"System":"phone","Value":"1234567890","Use":"work","Rank":1,"InUseStart":"2017-07-14T00:00:00","InUseEnd":"2017-10-22T00:00:00"},
{"ContactPointID":34,"EntityID":9,"System":"phone","Value":"1234567890","Use":"home","Rank":1,"InUseStart":"2017-07-14T00:00:00","InUseEnd":"2017-10-22T00:00:00"},
{"ContactPointID":35,"EntityID":9,"System":"fax","Value":"1234567890","Use":"work","Rank":1,"InUseStart":"2017-07-14T00:00:00","InUseEnd":"2017-10-22T00:00:00"},
{"ContactPointID":36,"EntityID":9,"System":"email","Value":"kishore@abc.com","Use":"work","Rank":1,"InUseStart":"2017-07-21T00:00:00","InUseEnd":"2017-10-29T00:00:00"},
{"ContactPointID":37,"EntityID":9,"System":"email","Value":"kishore@abc.com","Use":"home","Rank":1,"InUseStart":"2017-07-21T00:00:00","InUseEnd":"2017-10-29T00:00:00"}],

Below is HTML Syntax, where i need to get respective input values in value and system and use will be hard-coded values and validations based on system, any suggestions in achieving this will be very helpful

 <div class="col-md-4" formArrayName="ContactPoints">
                <div class="form-group form-group-default  " formGroupName=0>
                    <label class="control-label">Main Number</label>
                    <input type="text" class="form-control" formControlName="Value">
                </div>
            </div>

<div class="col-md-4" formArrayName="ContactPoints">
                    <div class="form-group form-group-default  " formGroupName=1>
                        <label class="control-label">Main Number</label>
                        <input type="text" class="form-control" formControlName="Value">
                    </div>
                </div>