T8402 and T8403 are all ICS Triplex Trusted range of Input/Output (I/O) modules. T8402 is Trusted Dual 24 Vdc Digital Input Module with 60 Channel. T8403 is Trusted TMR 24 Vdc Digital Input Module 40 Channel. Both of them Backplane (IMB) Supply is 20W, 20 to 32 Vdc, can be installed in T8100 or T8300 Trusted TMR Controller Chassis.  Due to the number of inputs are different, is T8403 can repl...