RFM IM1800

Preliminary
IM1800
®
• Application Interface Module for the DM1800 Transceiver Modules
• USB Host Computer Interface with Virtual Serial Port Driver
• Choice of USB or External DC Power Sources
• Supports Analog and Logic Inputs and a Logic Output
The IM1800 is designed as an application interface module for the DM1800 series transceivers.
The IM1800 can be powered from either its USB interface or from an external DC power input. The
IM1800 USB interface is supported by a host computer virtual serial port driver. In addition, the
IM1800 provides terminal block connections for an analog input, a logic input and a logic output.
Direct connections to the DM1800 transceiver module USART are also provided on the IM1800
terminal block.
Transceiver
Interface
Module
Absolute Maximum Ratings
Value
Units
VIN
Rating
-0.3 to +16.0
V
All Other Input/Output Connections
-0.3 to +4.0
Non-Operating Ambient Temperature Range
-50 to +100
V
o
C
Electrical Characteristics
Characteristic
Sym
Notes
Minimum
Digital Output Source Current
Digital Output Sink Current
Virtual Serial Port Data Rate
Typical
Maximum
Units
0.5
mA
1
mA
9.6
kb/s
o
VIN
3.1
14
V
Power Supply Input Voltage Range, 0 to +85 C
VIN
2.6
14
V
Power Supply Input Voltage Range, -40 to +85 C
o
Regulated Power Supply Output Voltage, VIN 3.1 to 14 V
VOUT
Current Available for External Circuitry
3.0
Vdc
10
1
mA
IM1800 Applications
serial interface should remain unconnected. The
IM1800 virtual serial port USB interface is based on the
Silicon Labs CP2101 IC. The CP2101 drivers can be
downloaded from www.silabs.com. After the correct
driver has been installed on a host PC, the USB interface will appear as a serial port.
The IM1800 is a companion interface board for the
DM1800 series transceiver modules. It has two uses:
First, the IM1800 can be used as a general purpose interface for DM1800 series transceiver modules. For this
application, the IM1800 provides a captured screw I/O
terminal block, a virtual serial port USB interface, and a
choice of USB, coaxial plug or terminal block for the DC
power supply input. For DM1800 base stations and field
nodes, the IM1800 supports serial communications
through the virtual serial port USB interface, or by direct
connection to the USART on the DM1800 module.
Bread Boarding Area
Referring to Figure 1, the IM1800 bread boarding area
is supplied with ground connections on eyelet Row 10
(vertical row of eyelets on right side), VOUT on eyelet
Row 3, and VIN on eyelet Row 2. VOUT and the I/O
signals from the DM1800 are also provided in two locations on Row 1. Refer to the table on Pages 3 and 4 for
Second, the IM1800 can be used as a development
details. Note that the DM1800 can provide up to 10 mA
platform for applications where a DM1800 series trans- for supplying external circuitry. Additional power can be
ceiver will be installed a customer’s board. In addition to provided by adding a 3 V regulator in the bread boardthe features listed above, the IM1800 provides a coning area and running it from VIN. Take caution not to
nector strip for jumpering a flat cable to a customer’s
operate circuitry from VIN that directly interfaces the
board (or for a logic analyzer/oscilloscope connection), DM1800 I/O signals to avoid damaging the DM1800
and a “bread board” area for building and testing interand/or IM1800. Note that any components placed on
face circuits.
the bread boarding area directly under where the
DM1800 module plugs in must be no taller than 0.1
Power Supply Options
inch.
The IM1800 will accepts an external DC power supply
voltage in the range of 2.6 to 14 V (3.1 to 14 V for extended temperature operation). This voltage is routed to
the 3 Vdc regulator on the DM1800 transceiver (see
description of J2-3 on Page 3 for VOUT characteristics).
The external power supply voltage can be connected to
VIN on terminal block J2 or to the coaxial power connector J6. The IM1800 can also be powered from the
USB connector J1. When the IM1800 is powered from
the USB connector, no connection should be made to
the VIN terminal on terminal block J2 or to the coaxial
power connector J6.
I/O and Power Supply Precautions
Note that all analog and digital input signals must be
within the range of 0 to VOUT. Applying a signal outside
of this range may damage the DM1800 and/or IM1800.
External DC power supplies must be in the range of 2.6
to 14 V. Suitable external power supplies include batteries and transformer isolated, regulated DC power supplies. Be cautious when using unregulated “wall
transformer” DC supplies. The output voltage of these
unregulated supplies can be much higher than the
nameplate value when powering low current loads.
Serial Port Options
Note: the IM1800 is equipped with a programming connector compatible with a Microchip MPLAB® ICD 2. Except in special circumstances, however, all DM1800
transceiver modules are shipped pre-programmed. Reprogramming a pre-programmed DM1800 transceiver
module will void the warranty and any regulatory certifications of the module.
The IM1800 provides direct connections to the DM1800
transceiver module USART on terminal block J2. Note
that the DM1800 USART I/O is 3 V CMOS logic. Alternately, the serial port on a DM1800 can be interfaced
through the serial port-USB bridge IC on the IM1800.
Only one interface should be used at a time; the other
2
Connector and Terminal Block Descriptions
Pin
Name
Description
J1-1
VBUS
J1-2
D-
This is the USB D- signal.
J1-3
D+
This is the USB D+ signal.
J1-4
GND
This is a signal and power supply ground for the USB connector.
J1-5
GND
This is a signal and power supply ground for the USB connector.
J1-6
GND
This is a signal and power supply ground for the USB connector.
J2-1
J3-1
J4-1
GND
This is a signal and power supply ground.
J2-2
J3-2
J4-2
VIN
This is the power supply positive input. The allowed input voltage range is 2.6 to 14 V.
This is the USB VBUS. The IM1800 and its DM1800 transceiver module can be powered from this supply.
J2-3
J3-3
J4-3
R1-7
R1-28
VOUT
VOUT tracks 50 to 100 mV below VIN when VIN is in the range of 2.6 to 3.1 V. When VIN is in the range of 3.1
to 14 V, VOUT is regulated at 3.0 Vdc. Up to 10 mA can be supplied for powering external circuits such as
thermistor-resistor networks. External circuitry must not impress more than 10 mVp-p ripple on the regulated
output voltage.
J2-4
J3-4
J4-4
R1-6
R1-27
BIND
This is connected to a logic input on the microcontroller, and is configured with a weak pull-up. When this pin is
momentarily grounded (to J1-1 or J1-10, the module is placed into the bind mode, allowing this module to be
associated with other modules to form a network.
J2-5
J3-5
J4-5
R1-5
R1-26
DIGITAL
IN
This is connected to a logic input on the microcontroller, and is configured with a weak pull-up, allowing both
logic signals and contact closures referenced to J-1 or J-10 to be read. The value of this input is sent over the
RF channel as a response to an RF command. The input voltage range on this pad is 0 to VOUT. Applying a
voltage outside of this range may damage the module.
J2-6
J3-6
J4-6
R1-4
R1-25
ANALOG
IN
This is connected to the input to the microcontroller’s 10-bit analog-to-digital (ADC) converter. The ADC input
range is 0 to VOUT, and the input voltage range on this pad is 0 to VOUT. Applying a voltage outside of this
range may damage the module. The reading is sent over the RF channel as a response to an RF command.
J2-7
J3-7
J4-7
R1-3
R1-24
DIGITAL
OUT
This is connected to a logic output on the microcontroller through a 1 kilohm resistor, which provides shortcircuit protection. The value of this output is set or read over the RF channel as a response to an RF command.
J2-8
J3-8
J4-8
R1-2
R1-23
SERIAL
RX
This is connected to the module’s serial data input (USART). Data to this input is received at 9.6 kb/s, using 8
data bits, no parity, and one stop bit. The input voltage range on this pad is 0 to VOUT. Applying a voltage outside of this range may damage the module.
J2-9
J3-9
J4-9
R1-1
R1-22
SERIAL
TX
This is the connected to the module’s serial data output (USART) through a 1 kilohm resistor, which provides
short-circuit protection. Data from this output is sent at 9.6 kb/s, using 8 data bits, no parity, and one stop bit.
J2-10
J3-10
J4-10
GND
J5-1
Vpp/~MCLR
This is a signal and power supply ground.
This is the programming connector microcontroller reset and programming voltage pulse input.
3
Pin
Name
Description
J5-2
VDD
This is the programming connector positive voltage input.
J5-3
GND
This is the programming connector ground.
J5-4
PGD
This is the programming connector data input.
J5-5
PGC
This is the programming connector clock input.
J5-6
-
J6-1
VIN
This is the coaxial power plug positive VIN input. VDD on J5-2 is disconnected when J6-1 is used.
J6-2
GND
This is the coaxial power plug ground.
This pin is not connected.
R 1 -2 8
P R O G R A M
(R J 4 5 -6 )
G N D
V IN
V O U T
B IN D
D IG IT A L IN
A N A L O G
IN
D IG IT A L O U T
S E R IA L R X
S E R IA L T X
G N D
U S B
(T y p e B )
R 1 -1
Figure 1
4
G N D
P a d L a b e ls
V IN
V O U T
V IN
IM 1 8 0 0 I/O
IM 1 8 0 0 M o u n tin g D im e n s io n s
1 .3
(3 3 .0 2 )
1 .7
(4 3 .1 8 )
0 .2 (5 .0 8 )
2 .6 (6 6 .0 4 )
0 .8 5
(2 1 .5 9 )
0 .2 (5 .0 8 )
0 .4
(1 0 .1 6 )
2 .4
(6 0 .9 6 )
m o u n tin g h o le d ia m e te r 0 .1 2 5 ( 3 .1 7 5 )
d im e n s io n s in in c h e s ( m m )
Figure 2
Note: Specifications subject to change without notice.
file: im1800h.vp, 2005.12.18 rev
5