An intrinsic safety barrier configured to be used in conjunction with at least one I/O module in an industrial process control and automation system comprising: a first hardware component comprising: at least one first input configured to receive at least one first data or power signal; at least one voltage clamping circuit configured to limit a voltage of the at least one first data or power signal; and at least one first output configured to provide the at least one voltage-limited first data or power signal; and a second hardware component comprising: at least one second input configured to receive at least one second data or power signal; at least one limiter circuit configured to limit an amount of energy in the at least one second data or power signal; and at least one second output configured to provide the at least one energy-limited second data or power signal, wherein, when the intrinsic safety barrier is in use, the at least one first output is coupled to one or more input of the at least one I/O module and one or more outputs of the at least one I/O module is coupled to the at least one second input, wherein the first hardware component and the second hardware component are packaged as separate subsystems that can be independently accessed and replaced and the intrinsic safety barrier supports the use of any types and numbers of I/O channels including at least one fixed and universal I/O channels of the at least one I/O module. a first hardware component comprising: at least one first input configured to receive at least one first data or power signal; at least one voltage clamping circuit configured to limit a voltage of the at least one first data or power signal; and at least one first output configured to provide the at least one voltage-limited first data or power signal; and at least one first input configured to receive at least one first data or power signal; at least one voltage clamping circuit configured to limit a voltage of the at least one first data or power signal; and at least one first output configured to provide the at least one voltage-limited first data or power signal; and a second hardware component comprising: at least one second input configured to receive at least one second data or power signal; at least one limiter circuit configured to limit an amount of energy in the at least one second data or power signal; and at least one second output configured to provide the at least one energy-limited second data or power signal, at least one second input configured to receive at least one second data or power signal; at least one limiter circuit configured to limit an amount of energy in the at least one second data or power signal; and at least one second output configured to provide the at least one energy-limited second data or power signal, wherein, when the intrinsic safety barrier is in use, the at least one first output is coupled to one or more input of the at least one I/O module and one or more outputs of the at least one I/O module is coupled to the at least one second input, wherein the first hardware component and the second hardware component are packaged as separate subsystems that can be independently accessed and replaced and the intrinsic safety barrier supports the use of any types and numbers of I/O channels including at least one fixed and universal I/O channels of the at least one I/O module.