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Kele • RUT-G Manual 2005 • www.kele.com • USA 888-397-5353 • International 901-382-6084
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RS232/485 INTERFACE KEY
Local Processor is the main Frontier Gateway control unit. This processor handles all data to and from the RF trans-
ceiver radio. The network interface key communicates directly with the local processor, making the processor trans-
parent to the user.
Lost Signal Response
is a value used to inform the network interface key on how to handle a lost signal from a field
transmitter. The lost signal response is valid only for network variable outputs and is set in the Output Configuration
Packet (Configuration Packet 3). A loss of signal is based on the maximum time interval. The data value will be forced
to a known value listed in "LOSS OF SIGNAL TYPE RESPONSE" in Table 3.
Network Interface Key Address is the address of the Gateway network interface key. For RS232 key applications,
this value will always be 0 with no previsions on the key for changing it. For RS485 applications, a dip switch on the
interface key is available to change the address with ranges of 1 to 255. If a 0 is selected on an RS485 key, it will be
disabled.
Network Interface Key
is the RS232 or RS485 hardware port allowing the user device to interface to the Gateway.
Refer to Figure 1 and Figure 2. For jumper settings, refer to Figure 5. For key types, refer to Table 7.
Network Variable Inputs are the network interface key inputs sent from the user device. They are the data transmit-
ted to the Frontier field receivers. The number of inputs is included in the Global Configuration Packet.
Network Variable Outputs
are the network interface key outputs sent to the user device. They are the received data
from the Frontier field transmitters. The number of outputs is included in the Global Configuration Packet.
Packets are multiple bytes (byte = 8 bits) of ASCII characters. Each packet starts with '<' (hex 0x3c) as the first byte.
Commas are used to separate data values. The first data item is the network interface key address. For RS232 ap-
plications, this value will always be zero (0). The second data value of each packet is the packet type, which identi-
fies what type of data is in the packet. The last byte in all packets is the '\r' (hex 0x0d) character, which indicates the
end of the packet.
Packet Acknowledge (ACK) Enable/Disable
is enabled or disabled in the Global Configuration Packet. ACK affects
the network interface key
and
user device. If enabled (set to 1), the sending device receives an acknowledgement
when the packet is delivered. For RS485 applications, the polled data is the ACK response. If set to 0, then no ac-
knowledgement will be sent. This condition is enabled/disabled in the Global Configuration Packet and will immedi-
ately affect
all
data packets including all configuration packets. It is recommended that the ACK be enabled to insure
data transfers are taking place.
An ACK is simply a return of the '>' (0x3Eh) character.
Example:
If data packet "<,AAA,5,65,2,6,35,15,33,1,\r" (AAA = key address) is received and ACK is enabled, the
ACK response from the receiving device to the transmitting device is '>'.
If an ACK is not received within 100 milliseconds, the network interface key attempts to retransmit the packet up to
six additional times. It is up to the software design of the user device to determine how many additional retries, if any,
to make.
Note: Because of the importance of the configuration packets, if an ACK from the network interface key is not
received by the user device, the retransmit from the user device should be indefinite. Configuration packets
are only received by the network interface key.
RS485 Applications: The user’s device must ACK a received packet or the network interface will retransmit as previ-
ously stated. Because RS485 network interface key is a polled-only device, the user device will not get an ACK from
the network interface key when given a polled request. This is because the requested polled packet is used by the
user device as the network interface key ACK response.
DEFINITIONS (CONTINUED)