APPENDIX A — INTERFACING XEROX PRINTERS | Page |
The OPTIMA provides several methods that allow SCS and XES documents to coexist in the same environment.
Coexistence
In order to eliminate the formatting conflicts that can arise when using XES commands to control document formatting, the OPTIMA provides two special modes of operation, one called PFS (Programmable Function String) suppression mode, and the other called FF (Form Feed) suppression mode. These two modes of operation can act independently or in unison.
When the OPTIMA receives SCS commands from the host system, it sends PFSs to the printer to simulate the behavior of the IBM printer it is emulating. PFSs contain the XES commands used to control the printer.
When the OPTIMA is in PFS suppression mode, it continues to receive and interpret SCS commands from the host system; however, it does not send the required PFSs to the printer. For the duration of PFS suppression mode, the system effectively loses the ability to control document formatting, allowing full control of the formatting via XES commands. When PFS suppression is active, the only PFSs sent to the printer are CR>, LF> and FF> PFSs.
When the OPTIMA is in FF suppression mode, any Form Feed characters received from the host system are ignored. This allows the user to fit an large number of XES commands on one physical page at the printer, even though the system thinks it is printing multiple pages.
The OPTIMA provides three general methods for initiating and terminating PFS and FF suppression modes. Two of these methods use embedded triggers in the data stream to delimit the section of the data stream where the PFS or FF suppression modes are to be active. Another method the OPTIMA provides for initiating and terminating PFS and FF suppression modes is the use of separate addresses.
Separate Addresses
Of the three methods used to control PFS and FF suppression, the use of separate addresses is probably the simplest. The idea behind the separate addresses method is that one twinax address can be configured on the OPTIMA to have PFS and/or FF suppression modes constantly active, and another address can be configured to have them inactive.
