What is the UIDDA? The UIDDA is short for the Uniform Interstate Depositions and Discovery Act. 
In order to issue a subpoena pursuant to the UIDDA, the subpoena from the trial state is presented to the clerk of the court in the county where discovery is to be made in the foreign state. Thereafter, the clerk, in accordance with their procedures, should promptly issue the subpoena directly to the individual or entity.
While the UIDDA was created to make discovery easier by removing the need for local counsel, judge's involvement or obtaining a commission, you will find that there is little uniformity given every state, every county down to every court clerk has their own procedures. 
Per the Uniform Law Commission's website:
UIDDA is efficient. The clerk of court in the discovery state acts in a purely ministerial
role, but in a manner that is sufficient to invoke jurisdiction of the discovery state over the

UIDDA is inexpensive. The Act eliminates the need for out-of-state litigants to obtain a
commission or local counsel in the discovery state and file miscellaneous actions during
discovery in order to subpoena individuals located outside the trial state.

UIDDA minimizes judicial oversight. Under the Act, there is no need to present the matter
to a judge in the discovery state before a subpoena can be issued.

UIDDA implements clear rules governing discovery. Discovery permitted by the Act
must comply with the laws of the discovery state. UIDDA recognizes that the discovery
state has a significant interest in protecting its residents who become non-party witnesses in
an action pending in a foreign jurisdiction from unreasonable or burdensome discovery
requests. Moreover, all motions to quash or modify a subpoena must comply with the law
of the discovery state. 
Is your state a UIDDA Participant? Check the Uniform Law Commission's website to see if your state has enacted a version of the UIDDA.