GE IC697ALG441 Analog Input Expander, Voltage
The RX7i control system hardware consists of an RX7i rack and up to seven Series 90-70 expansion
racks. The CPU resides in slot 1 of the main rack. RX7i racks use a VME64 backplane that provides up
to four times the bandwidth of existing VME based systems, including the current Series 90-70
systems for faster I/O throughput. The VME64 base supports all standard VME modules including
Series 90-70 I/O and VMIC modules.
Expansion racks support Series 90-70 discrete and analog I/O, the Genius Bus Controller, and the
High Speed Counter. The CPU provides an embedded auto-sensing 10/100 Mbps half/full duplex
Ethernet interface.
RX7i supports hot standby (HSB) CPU redundancy, which allows a critical application or process to
continue operating if a failure occurs in any single component. A CPU redundancy system consists of
an active unit that actively controls the process and a backup unit that is synchronized with the
active unit and can take over the process if it becomes necessary. Each unit must have a redundancy
CPU, (IC698CRE020, CRE030 or CRE040). The redundancy communication path is provided by
IC698RMX016 Redundancy Memory Xchange (RMX) modules set up as redundancy links. For details
on the operation of PACSystems redundancy systems, refer to the PACSystems Hot Standby CPU
Redundancy User’s Guide, GFK-2308.
Note: Extended operation with dissimilar CPU types is not allowed. During normal operation, the
primary and secondary units in an HSB redundancy system must have the same CPU model
type.
The primary and secondary units of an HSB redundancy system can have dissimilar model
types for a limited time, for the purpose of system upgrade only. Fail wait times for the higher
performance CPU in a dissimilar redundant pair may need to be increased to allow
synchronization.
RX7i communications features include:
■ Open communications support includes Ethernet, Genius, and serial protocols.
■ A built-in 10/100mb Ethernet interface that has dual RJ-45 ports connected through an auto sensing switch for upload, download and online monitoring.
This eliminates the need for rack-to rack switches or hubs. The CPU Ethernet Interface provides basic remote control system
monitoring from a web browser and allows a combined total of up to 16 web server and FTP
connections. For details on Ethernet Interface capabilities, refer to TCP/IP Ethernet
Communications for PACSystems, GFK-2224.
■ Two serial ports, one RS-232 and one RS-485.
■ An RS-232 isolated Ethernet station manager serial port.

The Current Source Analog Output Module has 4 words (8 bytes) of analog output data. A
Bus Interface Unit is required to provide this output data to the host and/or local
processor.
The module converts analog values from the host or local processor into output current.
Scaling for the module is performed by the Bus Interface Unit. Software Range Selection of 0
to 20mA and 4 to 20mA is available on a per-channel basis. Using the 0 to 20 mA range
requires the installation of an external wire jumper between JMP and RET.
The default scaling for this module is:
Eng Lo = 0
Eng Hi = 20,000
Int Lo = 0
Int Hi = 20,000
The default range is 0 to 20mA. The module is shipped with no wire jumper present. The
jumper must be installed to correspond to the module’s default range and scaling.
The 4–20mA range provides a fixed 4 milliamp offset (0mA = 4mA signal), with a 16mA
signal span. The 4mA offset remains as long as analog loop power is applied, even if the logic
power is off. Note that default outputs for loss of host communications require both
backplane power and analog field power.
A second output on each channel provides an uncalibrated voltage output. The 4 to 20mA
range corresponds to 0 to 10 volts. The 0 to 20 mA range corresponds to 0 to 12.5 volts. A
wire jumper is required for the 0 to 20mA range. Both voltage ranges have restricted load
current drive capability above 10 volts. Voltage can be used alone, or simultaneously with
current to drive meters or voltage input devices.
An OPEN WIRE diagnostic available per channel operates only on the current outputs. If
you are using only the voltage output of a channel, you should either disable the fault or
connect a dummy load of 250 to 800 ohms across the current terminals of the channel. An
OPEN WIRE fault will not affect the operation of the voltage output.
Output register values outside the capability of the module will drive the output to the
appropriate minimum or maximum level but will not generate a diagnostic fault.