l

0

The column heading “Direction” refers to the direction of signal flow as viewed from the printer.

“Return” denotes the twisted-pair return, to be connected at signal ground level. For the interface wiring, be sure to use a twisted-pair cable for each signal and to complete the connection on the return side. These cables should be shielded and connected to the chassis of the host computer and the printer.

l

l

All interface conditions are based on TTL level. Both the rise and the fall times of each signal must be less than 0.2 microseconds.

Data transfer must be carried out by observing the ACKNLG or BUSY signal. Data transfer to this printer can be carried out only after receipt of the ACKNLG signal or when the level of the BUSY signal is LOW.

Printing enabled/disabled signals and control conditions

The following table shows the relationship between printing being enabled or disabled, the on line/off line status, and the receipt of the data on/off control characters, DC1 or DC3.

DC1 /DC3 ERROR (Data

on/off

control)

DClIDC3 High

(Jl/ (no effect) interface)

DC1 High

Recv’d

DC3 High

Recv’d

DC1/DC3 Low (no effect)

*While printing is disabled, character data is being received and acknowledged so that the printer can look for another DC1 character, which would allow it to resume printing.

Technical Specifications

A-7