Asynchronous Terminals and Printer Processes Programming Manual

INTRODUCTION
NOTE
| ATP6100/CSSASYNC, including ATP6100/CSSASYNC for CLX
| support, and TERMPROCESS should not be used for continuous
| READ.
From the application programmer's point of view, the three
processes are virtually identical. With each process, you
interact with the terminal or printer through GUARDIAN 90 file-
system procedures such as OPEN, READ, WRITE, CONTROL, and CLOSE.
| Terminals and printers can be connected to controllers directly
| or by means of modems. The devices communicate through an
| RS-232C interface or a 20-milliamp (ma) current loop interface,
| depending on the controller. Most controllers support both.
| However, the 6105 and 3605 controllers do not have a current
| loop interface even though the SYSGEN default is current loop.
| Therefore, you should specify RS232 or EIA at system generation
| time when configuring serial printers or terminals attached to
| a 6105 controller or 3605 controller. Otherwise, CMI does not
| properly report that the RS-232C interface is being used.
|
|
| NOTE
|
| SYSGEN does not accept the RS232 modifier for devices
| controlled by TERMPROCESS or SERIALPRINTPROCESS. You must
| specify the EIA modifier to define the RS-232C interface
| for these devices.
|
|
|
| The 6106 and 3606 controllers, on the other hand, have both a
| current-loop interface and an RS-232C interface, and like the
| 6105 and 3605, the SYSGEN default is current loop. However,
| the 6106 and 3606 transmit current loop and RS-232C signals
| simultaneously but receive the signals from only one of the
| interfaces at a time. Therefore, to ensure that the controller
| receives all signals transmitted from your serial device, verify
| that the interface type defined for the individual serial device
| does not conflict with the interface type defined globally for
| all the devices attached to the controller.
1-2 November 1987