E F Johnson Company 2425M70 Benutzerhandbuch

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P25 Trunking supports data service on a P25 Trunking system using an EF Johnson 
Technologies radio and a portable computer. The radio communicates with the computer 
over the P25 Mobile Data Peripheral (MDP) Interface, which uses an RS232 hardware 
interface at 9600 bits/s. The following protocols are supported across the interface: 

• Point To Point Protocol (PPP) 

• Internet Protocol (IP) 

• Universal Datagram Protocol (UDP)

• Transmission Control Protocol (TCP)

The radio must be programmed for data operations on the Trunked IV & D system. The 
following parameters apply:

Data Registration On/Off - Enables/disables data registration. 

ICMP Echo - Enables the radio to send back an ICMP response once an ICMP request 
has been received.

CAI Data Max Tx Attempts - Selects the maximum number of times the radio 
attempts to send a CAI data packet. Attempts to send the data packet continue until the 
radio receives an acknowledgment confirming the successful receipt of the packet, or 
until the radio exceeds the selected amount of transmit attempts. 

Response Timer - Selects the period of time the radio waits for an acknowledgment 
that a CAI transmission is successful before it tries the transmission again. 

SNDCP Activation Wait Timer - Controls the time that a radio waits for the KMF to 
respond to a SNDCP context activation request. 

Rx Voice Interrupts Data - Enables/disables whether a voice call can interrupt data. 

Subscriber IP Address - The IP Address assigned to the subscriber for a PPP 
connection. 

Mobile Computer IP Address - IP address assigned to the mobile computer for a PPP 
connection. 

Tx Limited Patience - Selects the amount of time radio attempts to transmit a common 
air interface packet. Once time expires, radio ceases transmission. Times are 1 to 255 
seconds, infinite in increments of 1. The default is infinite. 

Min Response Timer - Selects the minimum amount of time that the radio waits for an 
acknowledgement of a successful CAI to be sent across the channel. Times are 50 to 
2000 msec., in increments of 50 msec. The default is 700 msec.