Ohio Rev. Code § 2941.401
When a person has entered upon a term of imprisonment in a correctional institution of this state, and when during the continuance of the term of imprisonment there is pending in this state any untried indictment, information, or complaint against the prisoner, the prisoner shall be brought to trial within one hundred eighty days after the prisoner causes to be delivered to the prosecuting attorney and the appropriate court in which the matter is pending, written notice of the place of the prisoner's imprisonment and a request for a final disposition to be made of the matter, except that for good cause shown in open court, with the prisoner or the prisoner's counsel present, the court may grant any necessary or reasonable continuance. The request of the prisoner shall be accompanied by a certificate of the warden or superintendent having custody of the prisoner, stating the term of commitment under which the prisoner is being held, the time served and remaining to be served on the sentence, the amount of good time earned, the time of parole eligibility of the prisoner, and any decisions of the adult parole authority relating to the prisoner.
The written notice and request for final disposition shall be given or sent by the prisoner to the warden or superintendent having custody of the prisoner, who shall promptly forward it with the certificate to the appropriate prosecuting attorney and court by registered or certified mail, return receipt requested. If the appropriate prosecuting attorney and agency having custody of the prisoner have previously agreed, then the written notice, request, and certificate may be sent by electronic mail or facsimile, in lieu of registered mail or certified mail.
The warden or superintendent having custody of the prisoner shall promptly inform the prisoner in writing of the source and contents of any untried indictment, information, or complaint against the prisoner, concerning which the warden or superintendent has knowledge, and of the prisoner's right to make a request for final disposition thereof.
Escape from custody by the prisoner, subsequent to the prisoner's execution of the request for final disposition, voids the request.
If the action is not brought to trial within the time provided, subject to continuance allowed pursuant to this section, no court any longer has jurisdiction thereof, the indictment, information, or complaint is void, and the court shall enter an order dismissing the action with prejudice.
This section does not apply to any person adjudged to be mentally ill or who is under sentence of life imprisonment or death, or to any prisoner under sentence of death.
R.C. § 2941.401