1769-OF2 Help.

Hi, I have a 1769-OF2 here and I just need to easily test if the outputs on it are working. What is the best way to do this?. I have it connected to a 1764-28BXB and a 1764-LRP. Thanks in advance.

The first thing you'll need is the Installation Instructions:

http://literature.rockwellautomation.com/idc/groups/literature/documents/in/1769-in049_-en-p.pdf

Pay particular attention to the Series letter; the Series B modules have an option switch to allow them to use an external 24V power supply instead of power across the backplane. In your test case you won't need the external PSU.

The easiest way to test these modules is to configure them for 0-10V output and just put a voltmeter across the output terminals. There's no need for a particular load when you're in Voltage mode.

How familiar are you with RSLogix 500 ? You need to configure the module in the I/O Configuration subsystem, and set the Configuration bits to make sure it's in 0-10V mode.

Since it will be attached to the MicroLogix base, the two output data words will be O:1.0 and O:1.1.

The specifications say this is a 14-bit card, and the full single-ended voltage range is 0 to 10.5 V.

2^14 = 16384, so placing the value 16384 in O:1.0 should product 10.5 volts on Output 0. A value of 8192 should product 5.25 volts, and so on.

Hi Ken,

Thanks heaps for your help, changing the configuration bits is where I was going wrong. Setting a value of 16384 is giving me 5.25 volts and 32767 10.5volts, what am I doing wrong?.

I overlooked the Output Data Format... you're using Raw/Proportional, where the maximum value of an Integer (32767) generates the maximum output of the analog channel (10.5 volts).

I forgot that in this mode the 14-bit range of the module is shifted left; Bit 0 doesn't have any effect, I think.

If you want to get into the way the other ranges work (Engineering Units, Scaled for PID, and Percentage Full Scale) there's details in the User Manual for the 1769 Analog modules (publication 1769-UM002).

Thanks once again . I'll check out the user manual.