HP E1368A manual Example Using the Scan Complete Bit, Example Multiple Channel Scanning

Figure 3-9. Example: Multiple Channel Scanning

Example: Using the Scan Complete Bit

You can use the Scan Complete Bit (bit 8) in the Operation Status Register of a switchbox to determine when a scanning cycle completes (no other bits in the register apply to the switchbox). Bit 8 has a decimal value of 256 and you can read it directly with the STAT:OPER? command (refer to the STATus:OPERation[:EVENt]? command in Chapter 4 for an example).

When enabled by the STAT:OPER:ENAB 256 command, the Scan Complete Bit will be reported as bit 7 of the Status Register. Use the HP-IB Serial Poll or the IEEE 488.2 Common Command *STB? to read the Status Register.

When bit 7 of the Status Register is enabled by the *SRE 128 Common Command to assert an HP-IB Service Request (SRQ), you can interrupt the computer when the Scan Complete Bit is set, after scanning cycle completes. This allows the controller to do other operations while the scanning cycle is in progress.

The following example monitors bit 7 in the Status Register to determine when the scanning cycle completes. For the example, use:

∙an HP-IB select code of 7, primary address of 09, and secondary address of 15 for the Microwave Switch

∙an HP Series 200/300 Computer with HP BASIC

Chapter 3 Using the HP E1368A/69A/70A Modules 41