The Input/Output (I/O) Receiver module is utilized in all I/O racks (except for the first I/O rack in a Remote I/O station) to provide an interface for address, data, and control signals between the Series Six CPU and I/O modules; it also provides a link in a daisy chain to other I/O racks. The I/O Receiver module features and benefits are summarized in Table 1.
The I/O Receiver module monitors three types of error conditions: Daisy-chain power and continuity of I/O racks downstream (CHAIN OK); parity of data output by CPU (LOCAL PARITY); parity of CPU output data, driven by an I/O Transmitter module, as detected by other I/O Receiver module(s) downstream (CHAIN PARITY).
Corresponding LED indicators, visible through the module faceplate, turn off when the module detects errors and function as troublshooting aids.
The module comes from the factory configured for installation in all intermediate I/O racks in the daisy chain; however, the u s e r is instructed to reconfigure this module to ensure proper termination of the I/O Bus if the module is to be installed at the end of the I/O station daisy chain. (Refer to NOTE on this page,) Refer to Figure 1 (next page) for I/O Receiver module specifications.
NOTE I/O Receiver module Model IC600BF800B differs from Model IC600BF800A with regard to the module configurations described above. With the 800A model, users were instructed to remove a pair of DIP-shunts from all modules to be installedinintermediate (non-terminating) I / O racks. In the 800B model, however, a jumper-pack is installed at the factory for use in intermediate racks and a pair of DIPshunts are provided for installation in the terminating, or last, I/O rack.
The user should also note that these models are electrically compatible and can be utilized in the same I/O station. The module also adds parity bits to bytes of data generated by resident I/O modules and transfers parity bits generated by I/O modules downstrea