specific symptoms

1. Does the application have a progn:unming logic error? Check the application's output data set on the host for the same formatting err'ors. This might

indicate an application program error.

2. Did the application abend? Check progt'am listings or host output for error messages.

3. Did the application format the data for a tertnlnc:d type other than the one emu 1 ute d by the Dis pIa y l'Jr i t e r ?

{t • Are the R e c e i ve F-0 r mat d ef a u Its 0 f the act i v e set u p com pat i b 1 e L-J i t h the

I~ecei ve job?

1. Does the applicfltion have a progt"amrning logic er-ror-? Check th£~ application's output data set on the ho~t for the same formatting errors. This might

indicate an application program error.

2. 15 a certain trapsmis:'iion code not printingf If so, verify that the code is defi ned in the uct i ve I<eyboard.

3 • A r' e com p at i b 1 eke vb 0 a r d s i n use at bot h lac a t ion s (s e e " C h a r act e r T f'iln 51 ab ^{0 "}

Problems" on pag~ 6-12)?

Additional Displaywriter Diagnostic

Tools

l.J hen ,.. e c e i v e d d a t a i sun i n tell i g i b.1 e, the Dis p 1 Cl ',litH" i t e r 5 end Con tin u 0 u 5 D a t a (5 e e

"Send Continuous Datu" on page 7-3) and Receiv~ Continuous Data (see "Receive

Continuous Data" on page 7-5) utilities can be used with complementary host programs to test the i ntegr i ty of the 11 nk.

If the ASYHC Trace function l.JCl5 on, the OlsplaVI'Jrlter "SYNC Trace (see "ASYNC Tr()ce"

on p age 7 - 11) c Cl n be u ~j P. d tor' e vie l'J t h ~ d a t a 5 t rea tn Cl s i t a p pea r son the 1 ink. I n val i d control char'()cters received by the Disp!aywriter, for example, are recorded in the ASYIlC display.

In order' for a graph; c character to be communi cated correctly, both the sendi ng and receiving parties must use the same l~ne-coele value to represent it. The l~ne-code

vulue selected by the Di 5pla~Il·Jt·iter to represent a particular graphic character depends on the keyboard in use (see "Appendi x A. Supported Keyboards" on page A-l).

If one or more gt'aphi c characters are not: bel ng communi cated correctly and mis-translations are occurring, the problem may be caused by:

• The sender and rece; ver lIsi ng eli fferent keyboards

• One si de us; ng ~JP assi gnments and the olher us; ng DP ass1 gnments

When problems in translation are discover€~d, the character sets used by each side and the line-code values of each character set should be examined for incompatibilities.

Some host operating systems offer On-line Test Support (OlTS), which is used to verify proper on-line operation in the normal ASYHC application environment. OlTS has a

number of exerci sers to assi st in the locat i on of fai lures wi thi Il the communi cati ons network.

During a session, OlTS can be accessed from the Displaywriter by sending a Request For Test (RFT) that specifies a test to be executed. To do this, the RFT should be created at the Di spluyv.Jri ter and stored on a data cll skette or keyed on11 ne.

Any data sent to the DisplaYl.Jriter as a result of the RFT is received and stored as a nor'mDI r'ecei ve job. The recei ved data can be di splayed and its contents reported to personnel at the host.

6-12 IBM Displaywriter Host Attach Programming Guide: ASYNC

Chapter 7. Communications Diagnostic Utilities

The Displaywriter System provides the Displaywriter operator with a number of communications diagnostic utilities for problem determination in an ASYNC

environment. These utilities (the ~SYNC Link Analysis Utilities) enable the operator to test and exercise the mod~m, the communications adapter. and the link.

The ASYHC link Analysis utilities are provided on a separate diskette (the Link Analysis Diskette). When necessary, support personnel can instruct a Displaywriter operator to load this diskette, access one or more of the utilities, and report the

information that appears on the display.

• Send Continuous Data-used to continuously send known data (hex '55') down the link

• Receive Continuous Data-used to receive a continuous known data pattern, detect errors in the pattern and log the error

• Data Return to Sender-used to return all receive data back to the link

• Control Modem Interface--used to control and display the EIA interface

• Display Error Log--used to format and display the ASYHC Error Log data

• Change Link Description--used to define the ASYNC environment Figure 32 shows how the ut iii ties are accessed.

Communication Link Analysis Diskette Inserted

I

V

I

I I

I

v

IASYNC link Analysisl

I

I

V

Individual Utility

When the Communication link Analysis diskette is inserted, the Communications linl(

Analysis menu (Figure 32) appears.

IL disklR diskl IKyb xxx

I

COMMUNICATIONS LINK ANALYSIS I D 11 Et'1

a ASYHC link Analysis b BSC link Analysis c Load Program

Type ID letter to choose ITEM; press EtHER: ^It

Figure 32. Communications Link Analysis Menu

Selecting ASYNC Link Analysis, 1D Q, from the Communications link Analysis menu causes the ASYNC Link Analysis menu (Figure 33 on page 7-3) to appear. As Figure 33 on page 7-3 shows, a Link Description Status line (line 3) indicates:

• The code set in effect

• line speed

• Parity

• the modem port in use

Once the ASYNC link Analysis menu appears, an individual utility can be selected.

Hote: A-fter a link is established, an operator can press Disc to disconnect the link.

7-2 IBM Displaywriter Host Attach Programming Guide: ASYNC

IASYNC Link Analysis