Request for help in VHDL troubleshooting

Hi there, sorry for the late reply.

Was tied up with work.

Below is the code for the program.

I tried signaltap on it and upon toggling the sensor 1/2, i was expecting it to enter into Ain/Bin state. But yet it seem to only trigger at the first try after reset. The subsequent tries has no response. Can help advise?

Thanks alot!

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_ARITH.ALL;
USE IEEE.NUMERIC_STD.all;
ENTITY Tcontrol1 IS
PORT( reset, clock, sensor1, sensor2,
sensor3, sensor4 : IN STD_LOGIC;
switch1, switch2, switch1a, switch2a : OUT STD_LOGIC;
track1, track2, track3 : OUT STD_LOGIC;
dirA, dirB : OUT STD_LOGIC_VECTOR( 1 DOWNTO 0 ));
END Tcontrol1;
ARCHITECTURE a OF Tcontrol1 IS
TYPE STATE_TYPE IS ( ABout, Ain, Bin, Astop, Bstop );
SIGNAL state: STATE_TYPE;
SIGNAL sensor12, sensor13, sensor24 : STD_LOGIC_VECTOR(1 DOWNTO 0);
BEGIN
PROCESS ( reset, clock )
BEGIN
IF reset = '0' THEN
state <= ABout;
ELSIF clock'EVENT AND clock = '1' THEN
CASE state IS
WHEN ABout =>
CASE Sensor12 IS
WHEN "11" => state <= About;
WHEN "10"=> state <= Bin;
WHEN "01" => state <= Ain;
WHEN "00"=> state <= Ain;
WHEN OTHERS => state <= ABout;
END CASE;
WHEN Ain =>
CASE Sensor24 IS
WHEN "11" => state <= Ain;
WHEN "10" => state <= ABout;
WHEN "01" => state <= Bstop;
WHEN "00" => state <= ABout;
WHEN OTHERS => state <= ABout;
END CASE;
WHEN Bin =>
CASE Sensor13 IS
WHEN "11" => state <= Bin;
WHEN "10" => state <= ABout;
WHEN "01" => state <= Astop;
WHEN "00" => state <= About;
WHEN OTHERS => state <= ABout;
END CASE;
WHEN Astop =>
IF Sensor3 = '0' THEN
state <= Ain;
ELSE
state <= Astop;
END IF;
WHEN Bstop =>
IF Sensor4 = '0' THEN
state <= Bin;
ELSE
state <= Bstop;
END IF;
END CASE;
END IF;
END PROCESS;
sensor12 <= sensor1 & sensor2;
sensor13 <= sensor1 & sensor3;
sensor24 <= sensor2 & sensor4;
Track2 <='0';
WITH state SELECT
Track3 <= '0' WHEN ABout,
'0' WHEN Ain,
'0' WHEN Bin,
'0' WHEN Astop,
'1' WHEN Bstop;
WITH state SELECT
Track1 <= '0' WHEN ABout,
'0' WHEN Ain,
'0' WHEN Bin,
'1' WHEN Astop,
'0' WHEN Bstop;
WITH state SELECT
Switch1 <= '0' WHEN ABout,
'0' WHEN Ain,
'1' WHEN Bin,
'1' WHEN Astop,
'0' WHEN Bstop;
WITH state SELECT
Switch2 <= '0' WHEN ABout,
'0' WHEN Ain,
'1' WHEN Bin,
'1' WHEN Astop,
'0' WHEN Bstop;
WITH state SELECT
Switch1a <= '1' WHEN ABout,
'1' WHEN Ain,
'0' WHEN Bin,
'0' WHEN Astop,
'1' WHEN Bstop;
WITH state SELECT
Switch2a <= '1' WHEN ABout,
'1' WHEN Ain,
'0' WHEN Bin,
'0' WHEN Astop,
'1' WHEN Bstop;
WITH state SELECT
DirA <= "01" WHEN ABout,
"01" WHEN Ain,
"01" WHEN Bin,
"00" WHEN Astop,
"01" WHEN Bstop;
WITH state SELECT
DirB <= "01" WHEN ABout,
"01" WHEN Ain,
"01" WHEN Bin,
"01" WHEN Astop,
"00" WHEN Bstop;
END a;