TRIO Process I/O uses the TRIO field bus connected to groups of intelligent, highly-reliable, field-mounted blocks. Fewer terminations are required because the TRIO Field Bus replaces many single and multiconductor cables. TRIO blocks are small, rugged and designed to accommodate mounting at the point of control. They can be individually installed on machines, mounted in junction boxes or grouped in racks and panels. TRIO blocks have approvals from a number of agencies for use in hazardous locations. Therefore, it is not necessary to mount the blocks in specially designed, purged enclosures.