Symmetricom 5401, 5402 manual RS-232 Input/Output, Operating Manual Operation

Operating Manual

Operation

3 — Operation

Neither the 5401 nor the 5402 have any external manual controls. Signal output amplitude is controlled by internal potentiometers, which are located as described in Chapter 2. All operational control of the DRO is accomplished by means of an RS-232 input/output port.

RS-232 Input/Output

The DRO has been equipped with an RS-232 interface using a 13-pin MS type connector designated as J14 RS232 on the 5401, and using a DB15 connector designated as J3 on the 5402. This serial port can be used to communicate with the DRO from a computer or a 'smart terminal.' All communication is in the ASCII format. The standard character protocol is 9600 BAUD, one start bit, eight data bits, none for parity, and one stop bit.

The connector pin assignments and designations for both connectors are given in Chapter 4.

All communication to the DRO comprises two or three categories of characters. The first category is a single character which is always an ASCII $ (Hex 24). This is the attention/log-on character. The second category is an ID ASCII character which is a command to the unit. The third category (which may or may not be applicable) is a series of ASCII data bits to input data into the DRO. Leading zeros must be used where necessary. For example, if the number to be input is fifty-two, and if the data field is a four digit number, then it must be entered as 0052.

If a mistake is made while inputting new characters (prior to the last character), issuing the "$" character will cause a reset, and the new (correct) characters can be input.

All command message inputs and response outputs end with Carriage Return (CR), Line Feed (LF).

When burst status is on, the unit will not send a response. However, configuration parameters can still be changed.

Table 1 on page 8 shows the functions available. The ASCII character is shown followed by its HEX equivalent. Comments pertaining to that specific function are also included for clarity.