National Instruments NI 9144 User Manual

Also see for NI 9144: User guide User guide Getting started guide

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National Instruments NI 9144 User Manual Manual pdf 5 page image

In the EtherCAT safe state, output modules are set to pre-defined safe values. By default, zerois the safe value in the output module channel configuration. You can change the safe valuesby writing to the appropriate object dictionary entries for your output module.Slave Timing ModesThe NI 9144 operates in free-run mode or synchronized mode using the EtherCAT distributedclock (DC).By default, free-run mode runs the conversion cycle at the rate of the slowest module. You canslow the free-run mode conversion cycle down by writing a minimum cycle time innanoseconds to index 0x3001.1 of the NI 9144.In synchronized mode, each conversion cycle begins with a signal from the EtherCAT master/scan engine. The NI 9144 procedures an error if the external cycle time is too fast for amodule. NI Indcom for EtherCAT only supports synchronized mode.Mounting the DeviceTo obtain the maximum allowable ambient temperature of 70 °C, you must mount the NI 9144horizontally on a flat, metallic, vertical surface such as a panel or wall. You can mount theNI 9144 directly to the surface or use the NI Panel Mounting Kit. The following figure showsthe NI 9144 mounted horizontally.Figure 3. NI 9144 Horizontal Mounting11. UpYou can also mount the NI 9144 in other orientations, on a nonmetallic surface, on a 35-mmDIN rail, on a desktop, or in a rack. Mounting the NI 9144 in these or other configurations canreduce the maximum allowable ambient temperature and can affect the typical accuracy ofmodules in the NI 9144. For more information about typical accuracy specifications forC Series modules and temperature deratings caused by different mounting configurations, visitni.com/info and enter the Info Code criotypical.Caution Make sure that no C Series modules are in the NI 9144 before mountingit.NI 9144 User Manual | © National Instruments | 5