49 CFR §220.315

1. (a)The railroad's program of operational tests and inspections under part 217 of this chapter shall be revised as necessary to include this subpart and shall specifically include a minimum number of operational tests and inspections, subject to adjustment as appropriate.
2. (b)When conducting a test or inspection under part 217 of this chapter, a railroad officer, manager, or supervisor is prohibited from calling the personal electronic device or the railroad-supplied electronic device used by a railroad operating employee while the railroad officer, manager, or supervisor knows or should have known that—
   1. (1)The train to which the employee is assigned is moving;
   2. (2)The employee is—
      1. (i)On the ground;
      2. (ii)Riding rolling equipment during switching operations; or
      3. (iii)Assisting in preparation of the train to which the employee is assigned for movement.