Siemens 6ES5-424 Technical Reference Manual page 2

Chapter 1
Hardware Description
1 .l General Description
The 6ES5-242 module consists of five high speed counters
which can be independent of each other, or cascaded. The
following is a general discussion of capabilities available with
the 6ES5-242 Counter Module. Details of these capabilities
and how to configure the module is presented in Chapter 2
of this manual.
1
.l .l
Gate Control
Each counter can be enabled with either an external field
signal or an internailly generated signal. A variety of signal
configurations is available for the gate inputs.
1.1.2 Inputs
Internally generated signals from the output of one of the other
counters, or output from one of the two internal scalers are
provided. External inputs are provided from each of the
counters, which can be connected to a user application.
1 .l .3 Outputs
The outputs may be used internally to feed another counter
or to trigger an interrupt; or externally connected to a user
function.
1
.l
.4 Interrupts
Counters 1 & 2 allow you to program the counter to generate
an interrupt when a specific count is reached. All of the
counters can generate an interrupt (if enabled) when the
counter's output becomes active. The counter's active state
can be defined by the user.
Gate inputs 1, 2, &
3 are connected directly to the interrupt
controller, and can be enabled to generate an interrupt when
they are active. The gate inputs signals can be selected for
active high or active low states. These three interrupts operate
separately and are not influenced by counters 1, 2, or 3.
1 .l -5 Scaler 1
An internal scaler is available whose five fixed frequency
outputs can be routed to the input of any of the counters or
the input of Scaler 2. The 2 MHz system clock is used as the
input frequency to the scaler. The outputs are scaled in factors
of 10 or 16 from the input frequency.
1
.l .6 Scaler 2
Scaler 2 is used to scale its input by a selectable factor between
1 and 16. The input can be selected from any of the counter
inputs, gate inputs, or Scaler 1 outputs. The output of Scaler 2
can be connected by a jumper, selectable on switches S5
or S6 to the counter inputs, or gate inputs of any of the five
counters.
1.2 6ES5-242 Block Diagram
The 6ES5-242 counter module is an intelligent peripheral
controlled by a 8085 microprocessor system. The module
uses the AM 9513 Counter Chip, which contains five
independent, high-speed 16-bit counters to perform the
counting operations. The AM 9519, an interrupt controller, is
used to control the user-programmable interrupt structure.
The firmware for the module is stored on a 4K byte EPROM.
A 1K byte CMOS RAM chip is used for data storage.
The counter and gate inputs and the counter outputs are
optically to the front connectors of the module. Figure 1-1 is
a block diagram of the logic on the 6ES5-242 counter module.
The control logic handles the interface between the 6ES5-242
and the PC.
Counter Module
Block Diagram
1
8085
1 1
8KEpm
1
I
I
Microprocessor
(4
K
firrnware)
(4 K
user)
(temp storage)
Interrupt
Controller
Figure 1-1 6ES5-242 Counter Module Block Diagram