AMETEK Lx Series II Programming Manual - Manual (Page 161)

Programming Manual Lx \ Ls Series II
157
7.7 Examples
7.7.1 Determining the Cause of a Service Interrupt
You can determine the reason for an SRQ by the following actions:
1. Determine which summary bits are active. Use
*STB? or
serial poll
2. Read the corresponding Event register for each summary bit to determine which events
caused the summary bit to be set. Use:
STATus:QUEStionable:EVENt?
STATus:OPERation:EVENt?
ESR?
Note: When an Event register is read, it is cleared. This also clears the corresponding summary
bit.
3. Remove the specific condition that caused the event. If this is not possible, the event may be
disabled by programming the corresponding bit of the status group Enable register or
NTR|PTR filter. A faster way to prevent the interrupt is to disable the service request by
programming the appropriate bit of the Service Request Enable register.
7.7.2 Servicing Questionable Status Events
This example assumes you want a service request generated whenever the AC source's
overvoltage, overcurrent, or overtemperature circuits have tripped. From Figure 7-1, note the
required path for Questionable Status conditions at bits 0, 1, and 4 to generate a service request
(RQS) at the Status Byte register. The required register programming is as follows:
1. Program the Questionable Status PTR register to allow a positive transition at bits 0, 1, or 4 to
be latched into the Status Event register. Use:
STATus:QUEStionable:PTR 19 (1 + 2 + 16 = 19)
2. Program the Questionable Status Enable register to allow the latched events to be summed
into the QUES summary bit. Use:
STATus:QUEStionable:ENABle 19
3. Program the Service Request Enable register to allow the QUES summary bit from the Status
Byte register to generate RQS. Use:
*SRE 8
4. When you service the request, read the event register to determine which Questionable
Status Event register bits are set and clear the register for the next event. Use:
STATus:QUEStionable:EVENt?