(a) A subpoena shall be issued only for the attendance of a witness or for the production of documentary evidence at final hearing. (b) A subpoena shall be issued to any county within the state either by the clerk of court at the request of the officer or the defendant, or by counsel who has entered an appearance in the case. (c) The service of a subpoena shall be by first class mail, if the person to whom it is directed waives personal service, as provided in Form B in the appendix to these rules. No fees or mileage need be tendered with service by mail. (d) If the person to whom a subpoena is directed does not waive personal service, the issuance and service of a subpoena shall be as provided in Rule 345, C.R.C.P., except as otherwise provided in this rule.