
Principles of Operation
105
Synchronizing Acquisition on Multiple Modules
DT9857 modules provide a Sync Bus (RJ45) connector that you can use to connect and
synchronize the analog input subsystems of up to four DT9857 modules. DT9857E modules
provide four Sync Bus (RJ45) connectors that you can use to connect and synchronize the
analog input and/or the analog output subsystems of up to four DT9857E modules. The
following sections describes how to use the Sync Bus connectors to synchronize the analog
input and/or analog output subsystems of multiple modules.
Synchronizing the Analog Input Subsystems of Multiple DT9857
Modules
When synchronizing the analog input subsystems of up to four DT9857 modules, one module
is the master and the other modules are slaves. You specify the synchronization mode (master,
slave, or none) of the analog input subsystem using software.
When configured as a master, the Sync Bus connector outputs trigger and clock signals to
connected slave modules. When configured as a slave, the Sync Bus connector accepts trigger
and clock signals from the master; the start trigger source on the slave module in is ignored in
this configuration since the Sync Bus is used as the start trigger. When configured as none (the
default mode), the DT9857 module uses the 48 MHz reference clock instead of the Sync Bus
connector. The synchronization mode remains set until changed or until the application exits.
You can connect multiple modules in one of two ways.
shows how to connect a
maximum of two DT9857 modules by daisy chaining them together through the Sync Bus
connector.
shows how to connect a maximum of four DT9857 modules by using an
RJ45 distribution panel, such as the EP386, where the panel contains four RJ45 connectors that
are wired in parallel.
Figure 37: Synchronizing the Analog Input Subsystems of Two DT9857 Modules by Daisy Chaining
the Sync Bus Connectors
Host PC
DT9857
Master
Master Analog Input Subsystem Settings:
Synchronization Mode is Master.
Start Trigger can be Software, External
Digital Trigger, or Threshold Trigger.
Reference Trigger can be External Digital
Trigger or Threshold Trigger.
If using a reference trigger, set up the
post-trigger scan count for the master.
Sync Bus (RJ45)
DT9857
Slave
USB
Port 2
USB
Port 1
USB
USB
Slave Analog Input Subsystem Settings:
Synchronization Mode is Slave.
Start Trigger is ignored (Sync Bus is used).
Reference Trigger is Sync Bus.
If using a reference trigger, set up the
post-trigger scan count for the slave.
Device
Under Test
Inputs
Inputs
Содержание DT9857
Страница 1: ...DT9857 and DT9857E UM 25656 N User s Manual Title Page ...
Страница 4: ......
Страница 10: ...Contents 10 ...
Страница 14: ...About this Manual 14 ...
Страница 15: ...15 1 Overview Hardware Features 16 Supported Software 19 Supported Accessories 22 Getting Started Procedure 24 ...
Страница 25: ...Part 1 Getting Started ...
Страница 26: ......
Страница 40: ...Chapter 2 40 ...
Страница 61: ...61 4 Verifying the Operation of a Module Select the Device 63 Acquire Data from an Analog Output Channel 65 ...
Страница 64: ...Chapter 4 64 ...
Страница 71: ...Part 2 Using Your Module ...
Страница 72: ......
Страница 75: ...Principles of Operation 75 Figure 32 Block Diagram of the DT9857E Module ...
Страница 126: ...Chapter 6 126 ...
Страница 127: ...127 7 Troubleshooting General Checklist 128 Technical Support 130 If Your Module Needs Factory Service 131 ...
Страница 132: ...Chapter 7 132 ...
Страница 140: ...Chapter 8 140 ...
Страница 180: ...Appendix B 180 ...
Страница 181: ...181 C Register Level Programming Writing to the EEPROM Register 182 ...
Страница 184: ...Appendix C 184 ...
Страница 192: ...Index 192 ...