Watlow Electric Revision 5 - Manual (Page 46)

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7.2.7 Open Thermocouple Detection
The RRIAM has upscale open thermocouple detection which is
accomplished by placing a small current through the thermocouple leads.
The input source impedance may go as high as 200 ohms before rated
accuracy is effected.
7.2.8 Address Selection
Each RRIAM has a jumper for address selection of the RRIAM in the
SYSTEM 32. As many as three RRAIM's may be used per system.
7.3 SOLID STATE ANALOG INPUT MODULE -- A32-SSAIM
The SSAIM is similar to the RRAIM except that the input channels are switched
with 2 wire solid state multiplexers instead of 3 pole reed relays. The result is less
voltage standoff [10volts maximum] between the inputs and the input grounds.
The number of input channels is increased to 32 at about the same cost of 16 reed
relay inputs.
The scan rate is still at 32 channels per second, thus each channel is updated every
second. The PIOM still scans the SSAIM's in parallel, thus additional SSAIM's
will not add to the scanning time.
The maximum number of SSAIM's per system is three. This gives a total of 96
inputs for a low cost data acquisition system.
Both RRAIM's and SSAIM's can be used in the same SYSTEM 32. The first 32
inputs are used for closed loop control.
7.4 ANALOG OUTPUT MODULE -- A32-AOM
The AOM is used when an analog output signal is required to control the final
control element. The 16 channel AOM provides a 4-20ma output [maximum load
400 ohms] or 0-5v output [5ma maximum]. Either output can be selected for each
loop on the terminal block.
Warning: Only one output may be used for each loop.
Other outputs are available upon special order, contact ANAFAZE.
The 8-bit Digital/Analog (D/A) converter supplies the necessary signal to the output
transistors according to the PIOM control calculations. The analog control output
for a particular loop verses a digital control output on the PIOM is software
selected.
The output transistors have a compliance voltage of 8vdc and all outputs share a
common ground which is isolated from the system ground.
Warning: The analog outputs must not be connected to devices that
feedback power line AC or other voltages to the AOM. If there is
voltage present optical isolators must be used. Please consult
ANAFAZE for more information.