In AXI3 VIP, getting assertion error as well default transaction type is being picked up with values zeroes being displayed

Hi,

Even though I have declared pif, it is showing as undefined variable. Not sure what’s the issue.
//declaring clk & reset
reg clk,rst;
//logic to get user input
initial begin
$value$plusargs(“testname=%s”,cfg_axi::testname);
cfg_axi::vif=pif;
end

	//instantiate interface
		intf pif(clk,rst);
	//testbench instantiate
		tb tb();

Error

** Error: ** while parsing file included at axi_header.svh(11)

** at top.sv(56): (vlog-2730) Undefined variable: ‘pif’.

End time: 07:03:48 on Feb 17,2021, Elapsed time: 0:00:00

Errors: 1, Warnings: 0

** Error: /home/tools/mentor/questasim/linux/vlog failed.

Error in macro ./run.do line 1

/home/tools/mentor/questasim/linux/vlog failed.

while executing

“vlog axi_header.svh”