NETPLEX Devices
While SENET is IGT’s bus for communication to simple devices such as lights and switches, NETPLEX is the bus for communication to complex devices. All NETPLEX devices are microprocessor based and communicate by transferring text messages to and from the game. Ticket Printers, Bill Acceptors, touch screen, VFD displays and more complex Top Box additions are NETPLEX devices.
This is also unique to IGT and is another feature that gives IGT games design flexibility for upgrading them to add-ons to make WAP’s like “I Love Lucy”, and other games with elaborate Top Box displays.
All NETPLEX devices are connected together as shown in the following diagram.
NETPLEX signals
The NETPLEX is an asynchronous serial bus. Unlike the Synchronous SENET there is no Clock Pulse to tell the bus device that data is there. Instead the data is sent out at a specific speed. The speed must be the same between the transmitting device and the receiving device. The leading edge of the initial signal starts the transfer process. Embedded in the protocol of the signal is the address of the device the information is intended for, the control code telling the device what to do with the data, then the data.
M RESET\ - Is Power-On Reset to set the device to a known state on power up, or restart it in case it gets hung up or confused.
NETPLEX RxD – NETPLEX RxD is the data line for information coming from a NETPLEX device to the MPU.
NETPLEX TxD – NETPLEX TxD is data from the MPU going to NETPLEX devices.
The other signals are power or ground. Most NETPLEX devices get their power from the bus. Not all.
All NETPLEX devices are connected together. A fatal problem on one device could affect all NETPLEX devices.
Hardware
J2, J3 J10, and J14 on the Backplane go to NETPLEX devices. Typically J2 goes to the VFD Display (if used). J3 goes to the Top Box NETPLEX devices (Ticket Printer). J10 goes to the Bill Acceptor. Through different generations of games this configuration has differed. It is not a hard rule. J14 is often dedicated to the Printer in some games.
NETPLEX devices are fed from one of the Serial channels. The basic 960 series game has eight such serial I/O channels that originate at U68 or U69 on the Logic Board. Each of these is a QUART (Quad Universal Asynchronous Receiver and Transmitter, SC26C94).
U68’s four channels control:
Data Collection System, J16 pins 1-5 (RS-485)
Chopped AC line input (Low Voltage Detect)
Tell Tale circuit
Data Collection, RS-232
Touchscreen
Fiber Optic On-Board communications.
Power-Save control
Silicon Serial Number chip
NETPLEX
U69’s four channels control:
IGT’s SMART system
Flash Memory Enable
Spare Fiber Optic, and some of the LED’s (DS2 and DS3)
Troubleshooting NETPLEX problems
If any individual NETPLEX device fails the problem is more likely to be in the individual device or its cable to the backplane. If all NETPLEX devices are dead remove them all, but one, and see if it will function alone. VFD display would be the simplest device. Once you have confirmed that NETPLEX is working you know the problem is not in the MPU board or backplane. Plug in other NETPLEX devices one at a time until you find the one that kills the NETPLEX system.
PLEASE REMBER TO TURN POWER OFF WHEN REMOVING OR INSTALLING ASSEMBLIES!
NETPLEX runs out of one channel on U68, a QUART. Also going to U68 are the Touchscreen, Player Tracking system (some times), and other devices. It is not likely that a problem on NETPLEX will damage the MPU board, but a problem on one of these other circuits could damage U68 and affect NETPLEX.