Diagnostics

Initializing the Terminal

Operator Control

The operator may initialize (or re-initialize) the terminal in any of the following ways:

Power-On. Each time the terminal is powered on, it goes through an Initialization procedure. In sequence:

Setup Z. Typing the 2-key sequence, SETUP Z, causes the terminal to go through the same Initialization procedure (as at power-on), except that it does not drop the DTR (Data Terminal Ready) signal to the host (pin 20 on the RS232 connector). This is the preferred method for re-initializing after power-on, because it does not break the connection to the host.

Reset key. Depressing CTRL-SHIFT-RESET causes the terminal to re-initialize, but starting after initialization of the Programmable keys (i.e. the Self Test is not repeated, and the existing contents of the Programmable keys are left undisturbed).

In all cases, if it is desired that the Power-on string NOT be executed, hold down the RESET key during the initialization. (The RESET key is checked prior to loading the Power-on string into the FIFO. If depressed, the string is not loaded, and hence not executed.)

Host Control

The host may initialize the terminal with the RIS (ESC c) control. This performs the same function as the operator's RESET key (i.e. starts with loading of the Power-on string). The host cannot initiate Self Test. The host cannot return the Programmable keys to their default values (but can re-program them to their default values; see Programmable Strings section).

NOTE: No data, including pads, should be sent to the terminal for at least 200 ms following an RIS control, to allow the terminal time to re-initialize its I/O. If the USART comes out of initialization in the middle of a received character, that character and probably following characters will be garbled, with indeterminate effect.

Data Line Monitoring

The Ambassador provides an extremely powerful Data Line Monitoring capability. This includes a unique Data Monitor Line (that permits monitoring the data without disturbing the terminal's normal operation or display), as well as a conventional full-screen Data Monitor (that can display the last 4800 characters received). Couple this with the Ambassador's Meta Monitor Mode (that permits the display of 8-bit data), and its ability to transmit (full-screen) monitored data back to the host, and you have a Data Monitor capability exceeding that of many high-priced commercial Data Monitors.

Normal Monitoring

The Received Data line (pin 3 of the Communications connector) normally accepts 7-bit data and parity. The Baud Rate, Parity, and Stop Bits expected are controlled by settings on Setup line B.

If Parity Detection (on Setup line B) is set, the parity of each incoming character is compared against the parity expected. If different, an error symbol (checkerboard) is displayed on the screen (instead of the character). The Data Monitor Line can be referenced to see what character the terminal thought it received.

If Meta Monitor Mode (zMMM, B,57) is set, the terminal is able to accept 8-bit data (in lieu of parity, i.e. the setting of Parity Detection does not apply). It may be used with the Data Monitor Line, or Transparent mode, to monitor 8-bit data. (When used with the Data Monitor Line, the low-order 7-bits are processed normally by the terminal.)

Data Monitor Line

The Data Monitor Line permits you to monitor the incoming data while the terminal is in normal operation. This can be used to see what the host is sending when you're first installing the terminal, or trying to use an unfamiliar system, or trying out a new piece of software, or simply to isolate a system probem to the terminal or the host.

Typing the 2-key sequence, SETUP M, brings the Data Monitor Line to the Screen. The line displays the last 79 codes that have been processed by the terminal. The SSA symbol (forward-pointing triangle) is used as a separator on the line. The last code processed is shown immediately before the symbol and the oldest code immediately after the symbol. The symbol appears as a needle pulling the string of characters around the Monitor line.

Graphic character codes (2/0 to 7/15 inclusive) are displayed as their graphic characters, just as they are in the text in the Window above. Control codes (0/0 to 1/15 inclusive) are displayed as a Reverse rendition of their corresponding upper-case characters, for easy identification.

If Parity Detection is set, characters received with Parity error are displayed with the additional rendition of Bold Underline. Examples:

A displayed Normal Upper-case A
A displayed Reverse CTRL-A (SOH)
A displayed Bold, Underlined A w/ parity error
A displayed Reverse, Bold, Underlined SOH w/ parity error

If Meta Monitor Mode is set, characters that have a high-order 'one' (i.e. 8th bit set), are displayed with the additional rendition of Bold Underline. Examples:

A displayed Normal Upper-case A
A displayed Reverse CTRL-A (SOH)
A displayed Bold, Underlined A w/ 8th bit=1
A displayed Reverse, Bold, Underlined SOH w/ 8th bit=1

Using the PAUSE key, in conjunction with this display, provides a powerful system debugging facility. You can operate the terminal normally yet, when an unexpected result occurs, pause, and review the sequence of codes that led up to it.

When the Data Monitor line is no longer needed, simply type the SETUP key twice to remove it from the display.

Transparent Mode

Transparent mode permits the entire display Page (up to 60 lines by 80 characters) to be used as a Data Monitor. The last 4800 codes received are stored, and may be viewed at one time. In addition, the captured data may be transmitted back to the host for analysis; see Send Controls section, zGRTM (Graphic Rendition Transfer Mode).

Typing the 2-key sequence, SETUP X, puts the terminal into Transparent mode. Incoming codes are displayed exactly as they were for the Data Monitor Line, except that now they are displayed in the terminal's Window, and the terminal's entire Page is available to store them; see Display section, Definitions.

When Transparent mode is no longer needed, simply type the SETUP key twice to return the terminal to normal operation.

Toggling into and out of Transparent mode, does not affect the data presently stored and displayed (until codes are received, whereupon they scroll up naturally in the Page). Thus, the mode may be used, at any time, to capture a few lines of incoming codes for analysis, without totally eliminating the context of what you're doing.

Local Test

Local Test mode is useful for performing terminal operations without involving the host, e.g. to exercise the terminal to see how a particular control (or control sequence) works, to enter (or annotate) data prior to a Page Print, or simply to test the terminal to isolate a problem to the terminal, host, or printer. The Data Monitor line is displayed during Local Test to permit you see exactly what codes you're entering.

Typing the 2-key sequence, SETUP T, puts the terminal into Local Test, with the Monitor line on the screen. The terminal's outgoing data line is wrapped back into its incoming data line within the terminal's communications interface. Codes are not sent to or received from the host. (However, the Data-Terminal-Ready output at the Communications connector remains 'on'.)

Typing the SETUP key twice, removes the Data Monitor line from the screen and returns the terminal to normal operation.

Self Test

The Ambassador performs a Self-Test procedure each time it is powered on (and in response to SETUP Z; see Initialization, above). In sequence:

If an error is found, the bell beeps, a 'MEMORY ERROR' flag is set, and the tests are re-started (from the beginning). Later in the initalization, if the NVM checksum does not verify, a 'CHECKSUM ERROR' flag is set. Upon completion of the initialization, if either error flag is set, the error message is displayed.

The following conclusions follow from observed results:

If the terminal beeps more than once, but the cursor appears and no error messages are displayed, the power supply is having trouble starting. This may indicate a power supply problem, but may also occur if the terminal is cold or the line voltage is low.

If the terminal beeps repeatedly and no cursor appears, the terminal has encountered a hard failure in its Self Test. The tests may be aborted, and the terminal forced to display, by holding down any key. The terminal may or may not operate correctly, depending on where and how bad the error is. If it does operate correctly, the trouble may be further localized with the diagnostics under Memory Errors below.

Checksum Errors

A CHECKSUM ERROR message indicates that the contents of NVM have changed since they were last saved. If you wish to disregard the error and continue operating, go into Setup mode, review and correct the terminal settings, and type the letter, S, to re-save them.

Repeated Checksum errors indicate a problem with the battery or with the CMOS RAM (PC board position 16H or 18H; see Technical Manual), and should be checked out by a qualified service person. The battery is a 3V lithium type (Panasonic #BR2325mm LI (wPCmt) 3V or equivalent) located in a plug-in socket on the Logic daughter board. It should last for 2-3 years of normal operation.

Memory Errors

A MEMORY ERROR message indicates that one or more errors were detected during Self Test. If you wish to disregard the error and try operating anyway, depress CTRL-SHIFT-RESET. This re-initializes the terminal without performing the Self Test.

NOTE: The memory tests are run with worst-case timing, i.e. worse than in normal operation. It is quite possible to get an error message, and find that the terminal works normally. The error message is an 'alert' that something is becoming marginal.

To determine where the errors occurred, enter Setup mode and display line D. The last number in the line shows the location (i.e. PC board position; see Technical Manual) of the last error found:

Note: A number between 1-63 tells which RAM or RAMs, according to the binary weighting 1=3E, 2=4E, 4=5E, 8=6E, 16=7E, 32=8E.
1-63 = Display RAM error (positions 3E-8E; see Note)
99 = Program ROM error (position 3F, 6F, or 8F)
128-135 = Working RAM error (position 5F)

The test results do not necessarily say that a RAM is 'bad' – only that the terminal found one or more errors in reading or writing it. This may be the result of a bad RAM, but it may also be the result of a mis-adjusted power supply voltage or an associated logic chip.

SETUP Y

If an intermittent error is suspected, the memory tests may be run repeatedly (e.g. overnight) by typing the 2-key sequence, SETUP Y. The bell will beep each time an error is detected. The tests will end when any key is held down on the keyboard. The last error found, if any, will be displayed in Setup line D.

NOTE: Before starting the tests, make sure that the number at the end of line D is zero (since it is overwritten only if an error occurs).